Is Intermittent Fasting "Diabesity Incompatible"? Increase in Glucose Excursions (+20-40%) + Impaired Insulin Response During Lunch and Dinner After Skipping Breakfast in T2DM

Whether having breakfast will help or hinder glucose control will also depend on its macronutrient composition and carbohydrate content. In their 2011 study Pereira et al. were able to show that a high carbohydrate, high GI breakfast will have a similarly negative impact on glucose control of adults and children as having no breakfast at all (Pereira. 2011). 

Intermittent fasting (IF), i.e. skipping breakfast and/or other meals in order to stay fasted for ~16h+ per day is no longer "all the rage", but still highly popular among people who believe in its health and weight loss benefits. And in fact, there is some research (also from a couple of Ramadan studies) that appears to confirm the notion that it is healthy and may - even without deliberate caloric restriction - facilitate weight and more importantly fat loss.

On the other hand, intermittent fasting conflicts with everything we've been (falsely?) told about the benefits of frequent meals. Benefits of which SuppVersity readers know that they are quasi-non-existent, in most healthy individuals and sometimes even counter-productive in obese and diabetic individuals, where most studies refute that eating more frequently provides significant weight loss benefits in the context of a calorically restricted diet.

Do you have to worry about fasting when your're dieting!?

Breakfast and Circadian Rhythm

Does Meal Timing Matter?

Habits Determine Effects of Fasting

Breaking the Fast & the Brain

Does the Break- Fast-Myth Break?

Breakfast? (Un?) Biased Review

Now, a recent study from the Diabetes Unit, Wolfson Medical Center of the Sackler Faculty of Medicine at the Tel Aviv University, the Lund University in Sweden and the Hebrew University of Jerusalem (Jakubowicz. 2015) suggests that extending your overnight fast by skipping breakfast may have real (not just corollary) detrimental effects on habitual breakfast eaters (learn why this is important) who are suffering from type II diabetes (with glycated hemoglobin (HbA1c) levels of 7–9% (the subjects in the study at hand were more than just pre-diabetic).

In this group of subjects, skipping breakfast increases post-prandial hyperglycemia (PPHG) after lunch and dinner. It lowers the important GLP-1 response to the meals (learn more about how GLP-1 is important in "Eat More, Burn More and Lose Fat Like on Crack with GLP-1!?") and impairs the subjects' already messed up insulin response. More specifically,

• 

  Three meals may be ok, but six meals are actually counterprodutive in T2DM.

  the lunch AUC0-180 for glucose, FFA, and glucagon were 36.8, 41.1 and 14.8% higher, respectively, and the AUC0-180 for insulin and  iGLP-1 17.0% and 19.0% lower, respectively, on the NoB[reakfast] day compared with the YesB[reakfast] day (P < 0.0001), 
• the dinner AUC0-180 for glucose, FFA, and glucagon were 26.6, 29.6, and 11.5% higher, respectively, and the the AUC0-180 for insulin and iGLP-1 were 7.9% and 16.5% lower on the NoB day compared with the YesB day (P < 0.0001), on the other hand

In conjunction with the 30% delayed insulin peak after lunch and dinner on the NoB[reakfast] day that's bad news for anyone who has pre-existing problems with managing his blood glucose levels. 

Figure 1: While the increased glucose and impaired insulin and GLP1 response to lunch and dinner are bad, the skyrocketing FFA levels (+1,787.1%) could be used as fuel - by metabolically healthy individuals (data based on Jakubowicz. 2015).

The authors' conclusion that their study "shows a long-term influence [of eating / skipping] breakfast on glucose regulation that persists throughout the day" (Jakubowicz. 2015), is thus absolutely correct - at least in the short run.

Adjusted linear regression coefficients for 24h EI in T2DM patients according to EI at breakfast in % of total EI (Jarvandi. 2014).

While there are other benefits, the greatest benefit of skipping breakfast ideally is a reduced total energy consumption. If you are like the average type II diabetic of whom recent studies indicate that he will increase, not decrease, his energy intake when he skips breakfast (Jarvandi. 2014), or if you're looking at a study where the dietary prescription made it impossible to reduce the total energy intake, the overall effect of skipping breakfast on the body fat levels and metabolic health is likely going null or even negative. So, yes: Calories count - not just with intermittent fasting, by the way.

Whether the conclusion that "[b]reakfast consumption could be a successful strategy for reduction of PPHG [prostprandial hyperglycemia] in type 2 diabetes" applies to every type II diabetic is yet as questionable as the assumption that you could extrapolate the data from this acute phase study and use it to predict the long-term response in diabetics, let alone health individuals.

Figure 2: Hunger, satiety, plasma glucose and insulin in the Eaters and Skippers in the two conditions in Thomas (2015).

If we go back to Thomas' recently published study (I have discussed it in detail here), it is after all obvious that the scientists choice of subjects who consume breakfast regularly may have thwarted their results. I mean, the researchers from the University of Colorado School of Medicine and the Denver Health Medical Center have shown quite conclusively that one's breakfast habits will determine whether skipping breakfast increases insulin, hunger and blood lipids or not.

Practically speaking, the results of the previously discussed study by Thomas et al. (2015) imply that by replacing the habitual breakfast eaters in the study at hand by habitual breakfast skippers, the results could have been very different. Against that background and in view of the fact that Jakubowicz's study with its isocaloric lunch + dinner meals (700kcal) did not allow intermittent fasting to work its true, energy intake reducing magic, I would not overrate the practical significance of the study at hand.

Figure 3: In 1992 Schlundt et al. were able to show that habitual breakfast skippers and eaters will lose the most weight on a std. weight loss inter-vention if they are forced to give their beloved breakfast habits up.

This is all the more true in view of the fact that Schlundt et al. were able to show that the success of a 12-week weight loss intervention can depend on deviating from your breakfast habits. In said study obese habitual breakfast skippers and eaters lost the most weight if they had to follow an unaccustomed eating pattern (see Figure 3) - that's not necessarily in contrast to Thomas' results, though. After all, we are dealing with acute metabolic (Thomas) vs. long-term body weight (Schlundt) data and by now you should know that these are two completely different pairs of shoes.

Against that background, I'll simply repeat my previous recommendation: If you feel intermittent fasting works for you, stick to it! Be careful, though and don't tell yourself that it would make you lose weight if it does not help you to cut your energy intake - that's very unlikely | Comment on FB!

References:

• Jakubowicz, Daniela, et al. "Fasting Until Noon Triggers Increased Postprandial Hyperglycemia and Impaired Insulin Response After Lunch and Dinner in Individuals With Type 2 Diabetes: A Randomized Clinical Trial." Diabetes Care (2015): dc150761.
• Jarvandi, Soghra, Mario Schootman, and Susan B. Racette. "Breakfast intake among adults with type 2 diabetes: influence on daily energy intake." Public health nutrition (2014): 1-7.
• Pereira, Mark A., et al. "Breakfast frequency and quality may affect glycemia and appetite in adults and children." The Journal of nutrition 141.1 (2011): 163-168.
• Schlundt, David G., et al. "The role of breakfast in the treatment of obesity: a randomized clinical trial." The American journal of clinical nutrition 55.3 (1992): 645-651.
• Thomas, E. A., Higgins, J., Bessesen, D. H., McNair, B. and Cornier, M.-A. (2015), Usual breakfast eating habits affect response to breakfast skipping in overweight women. Obesity. doi: 10.1002/oby.21049

HMB For Endurance Athletes: 3g Regular HMB Make Elite Rowers Run Out of Breath 10% Later + Facilitate Fat Loss

HIIT on the rowing machine is a powerful fat loss tool even w/out HMB. It's yet also pretty intense, so I'd suggest that you don't do it everyday | learn more

You will probably remember Jacob Wilson's impressive 2014 HMB study (Wilson. 2014 | read more). A study that repopularized an old supplement that was once marketed as being "as potent as a weak steroid". Steroids, however, are not exactly the #1 doping agent for endurance athletes. While many (ab)use everything that could improve their performance, agents like erythropoietin (EPO) are obviously much more popular.

Against that background it is not totally obvious to do what Krzysztof Durkalec-Michalski and Jan Jeszka did in their latest study: To assess the effect of HMB supplementation on physical capacity, body composition and levels of biochemical markers in endurance athletes, elite rowers to be precise.

Learn more about the potential beneficial effects of HMB at the SuppVersity:

HMB For Fat Loss?

Hica & HMB in Yogurt

More on HMB Free Acid

Breakthrough HMB Science

HMB + Whey = Useless?!

HMB Hampers Fat Loss?

The study design was simple, yet effective: 16 elite male rowers, aged 20± 2 years, with a body weight of 87.3 ± 9.8 kg and a height of 187 ± 5 cm consumed 3×1 g HMB/day or an identically looking placebo for 2×12 weeks. "2×12"? Yes, the study wasn't just randomized, placebo controlled, and double-blinded, it was also a crossover study with a 10 days washout period between the first and the second 12 week period. This makes the results more reliable - in spite of the low number of subjects.

Figure 1: Overview of the design of this double-blind, randomized, controlled crossover trial (Durkalec-Michalsky. 2015)

Before and after the two 12-week phases, aerobic (maximal oxygen uptake, ventilatory threshold) and anaerobic (anaerobic power indices) capacity were determined and analyses of the body composition as well as levels the creatine kinase, lactate dehydrogenase, testosterone (T), cortisol (C) levels and the T/C ratio were conducted.

Figure 2: While it looks like there was a sign. testosterone (T) boost in the HMB group, the p-value is 0.569. Accordingly, only the fat mass changes showed sign. inter-group differences (Durkalec-Michalsky. 2015).

What the analyses of these data revealed was quite conclusive: The provision of "regular" calcium HMB at a dosage of "only" 3g/day had a highly significant "advantageous effecton the increase in aerobic capacity and the reduction of fat mass" (Durkalec-Michalsky. 2015). More specifically,...

• 

  Figure 3: Changes in maximal oxygen uptake and rates at ventilatory threshold after 12-week supplementation of HMB. Values are expressed as mean ± SD. Significant differences compared with placebo (independent samples t-tests) at: *- p = 0.03; †- p = 0.012, ‡- p = 0.002; #- p < 0.001. VO _ 2 max: maximal oxygen uptake; TVT: time to VT; WVT: load at VT; HRVT: HR at VT (Durkalec-Michalsky. 2015).

  the subjects' VO2 max increased (+2.7 mL/min/kg) significantly (p < 0.001) in comparison to PLA where it was even slightly reduced (−1.0 mL/min/kg), 
• the ventilatory threshold, the threshold load, and the heart rat, which are the time-point, wattage, and heart rate at which further increases in respiration will no longer lead to increases in VO2 intake, were postponed by +1.2 min, +0.42 W, and +9bpm, respectively,
• with -0.9 kg the subjects in the HMB group lost body fat, while the subjects in the PLA groups gained 0.8 kg (p = 0.03), and lastly
• the refusal time to continue (a proxy of short term recovery) in the progressive test was extended (p = 0.04), maximum load (p = 0.04) and anaerobic peak power (p = 0.02) increased. 

What is interesting is that all these benefits occurred in the absence of changes in anaerobic adaptation or blood marker levels. This is cool, but it's also a problem, because as long as we don't know the mechanisms, it's hard to predict (a) who would benefit (most), (b) which supplements would act as synergists and (c) which supplements work via the same pathways so that taking them would make the use of HMB obsolete.

Breakthrough HMB Research: Additional(!) 10% Reduction in Body Fat, 5% Higher Lean Mass + 2x Higher Strength Gains After 12W of Heavy Lifting in Trained Individuals | more

So what do we make of the results? There's little doubt that Durkalec-Michalsky's latest study confirms that HMB can be useful not only for resistance trainees or sprinters, but also for athletes who are competing in sports with an endurance focus. Furthermore, it is yet another (non-sponsored) study to prove that it does not take the expensive free-acid form of HMB to see results.

What the study doesn't tell us, though, is whether the effects would remain significant if the subjects had been on the "athlete standard stack" consisting of creatine and whey protein. In view of the fact that there's no way to tell what mediated the VO2 and power improvements, it's also impossible to judge how likely it is that the co-ingestion of the aforementioned supps would marginalize the benefits.

So what? While it may be worth trying HMB, future studies with a focus on the mechanisms and the interactions with other supplements are still warranted | Comment on Facebook!

References:

• Durkalec-Michalski, Krzysztof, and Jan Jeszka. "The efficacy of a β-hydroxy-β-methylbutyrate supplementation on physical capacity, body composition and biochemical markers in elite rowers: a randomised, double-blind, placebo-controlled crossover study." Journal of the International Society of Sports Nutrition 12.1 (2015): 1-11.
• Wilson, Gabriel J., et al. "The effects of 12 weeks of beta-hydroxy-beta-methylbutyrate free acid supplementation on muscle mass, strength, and power in resistance-trained individuals: a randomized, double-blind, placebo-controlled study." European Journal of Applied Physiology (2014)

Trying to Shed That Belly? Step Off the Treadmill and Grab Some Weights, Boys & Girls! 19x More Visceral, 1.5x Higher Subcutaneous Fat Loss W/ Resistance Training in Youths

Specifically for teenagers it may be important to work out in both aerobic and anaerobic workouts. So, this would be another reason to favor the combined over the other regimen.

You will probably have overheard the "knowledgeable" trainers at the gym tell their credulous clients, who just told them they "want to lose that belly fat", that the best thing they could do was to "stop spending that much time with weight training" and to do some more (steady state) cardio. Well, in general, there's nothing wrong about steady state cardio - in fact, many studies show that it is superior to resistance training when it comes to "merely" shedding body weight (in the obese). If "weight loss" is still everything you're aspiring, though, you are either new to the SuppVersity or another of the "headline skimmers" who happen to ask questions that are answered not just in the article, but actually in one of the red boxes... ah, I am digressing.

So, what I actually wanted to tell you is that a recent study from the Universities of Ottawa and Calgary (Alberta. 2015), clearly contradicts the average commercial gym chain trainer's recommendation and shows that belly fat loss is better achieved with diet + resistance training.

Are you looking for muscle builders for the year 2015? Find inspiration in these articles:

Tri- or Multi-Set Training for Body Recomp.?

1, 2, or 5 sets per Exercise? What's "best"?

Pre-Exhaustion Exhausts Your Growth Potential

Full ROM ➯ Full Gains - Form Counts!

Battle the Rope to Get Ripped & Strong

Study Indicates Cut the Volume Make the Gains!

The subjects of the study were youngsters, 304 (! the high number of participants is a huge plus of the study) 14-18 year-old overweight and obese teenagers (mean body fat almost 50%!), to be specific, who were randomized to four different treatments for 22 weeks:

Table 1: Training progression in the Aerobic
and Resistance group (Alberga. 2015)

• aerobic training (Aerobic), 
• resistance training (Resistance),
• combined aerobic + resistance training (Combined) or 
• non-exercising control group (Control)

Adolescents,... ok, but unless they're too sarcopenic (=suffer from pronounced age-induced muscle loss) to hit the weights, your overweight clients or you, yourself, should be able to follow the same training programs the adolescents did and see similar results if you fully adhere to the following training prescriptions:

• Resistance: The duration of each session progressed to a maximum of about 45 min. Exercises were primarily performed on weight machines, and when required with dumbbells (lateral raise, shrugs, bicep curls, front raise, preacher curl, dumbbell pullover) or by using one's own body weight as resistance (lunges, sit-ups and abdominal crunches).
  

  

  Table 2: Overview of the individual workouts in the Resistance group (Alberga. 2015).

  Participants alternated among exercises from groups A1, A2, B1 and B2 shown in Table 2. Participants were asked to rest for ~ 2 min between sets and were instructed on proper breathing techniques.
• Aerobic: Participants randomized to the aerobic training group underwent a 22-week program (Table 1, left) wherein the exercise intensity and duration increased progressively to a maximum of 45 min per session. Exercise was performed on a cycle ergometer, elliptical or treadmill and participants were free to vary the machine(s) used. Exercise intensity was standardized using heart rate monitors (Polar Electro Oy, Kempele, Finland).
• Combined: This group performed the full exercise programs done by both the aerobic and resistance training groups (Table 1, left + right) during each session for a total of 4 times per week for a maximum of 90 min per session.

Now for simplicity we assume that you'd actually achieve not just similar, but rather the exact same results as the virtual "average" study participant from Alberta's trial. In this case, I bet that most of you would prefer to lose -22.7 cm² subcutaneous body fat with resistance training than -16.2 cm² or -18.7 cm² with either aerobic or combined training. Specifically in view of the fact that only resistant and combined training triggered measurable reductions in visceral body fat, too.

Figure 1: Changes in subcutaneous (SAT) and visceral (VAT) body fat at different regions; L4L5 represents area between 4th and 5th Lumbar vertebrae; * indicates sign. difference to control; # sign. difference to aerobic (Alberga. 2015).

On the other hand, a closer look at the body fat data in Figure 1 also shows that aerobic training is the only form of training that will reduce the deep subcutaneous fat, significantly. Plus: When it's done in combination with resistance training the reductions in subcutaneous fat at L4L5, which represents the area between 4th and 5th Lumbar vertebrae, are still statistically significant and not significantly smaller than those the subjects in the resistance training only arm of the study achieved. 

Figure 2: Changes in Apo-B and Apo-B/A ratio in the three exercise and the control group (Alberta. 2015).

What may eventually tip the scale in favor of the combined training regimen, though, is not the body composition data, but rather the fact that only the combined training routine triggered statistically significant, heart healthy changes in Apolipoprotein B and the Apolipoprotein A/B ratio. After all, the latter has "repeatedly been shown to be a better marker than lipids, lipoproteins and lipid ratios" (Walldius. 2006) - scoring in the top tertile for the ApoB/A ratio, for example has consistently been associated with 89% increased risk of heart disease (Thompson. 2006) .

Figure 3: In their 2005 trial, Tufts scientists were able to show that dietary adherence, not macronutrient comp. or other diet-specific parameters is the main determinant of weight loss (Dansinger. 2005).

You must never forget, however, ... that (a) the beneficial of all four exercise regimen were achieved in the context of an energy deficit of albeit relatively, but consistent -250 kcal/day, that (b) the study had a 4-week lead-in during which all participants that didn't show at least 80% adherence to the dietary + exercise baseline intervention were kicked out, and that (c) subjects who did not attend an average 2.8 out of 3.0 workouts per week were not included in the analysis the data in Figures 1-2 is based.

This obviously leads back to Energy restriction and adherence - the two usual suspects. Without them, any effort to shed the hated body fat must fail. With them, however, only perseverance and consistency may keep from achieving your fat loss goals.

You don't believe that? Well, check out the data in Figure 3. Dansiger and his colleagues from the Tufts University tried to find out which diet, i.e. Ornish, Zone, Weight Watchers, or Atkins die, would cut the most body weight. What they found, though, was that it's always the diet the subjects could adhere to that worked the best. Against that background, it's no wonder that, in the study at hand, only those participants who had more than the minimal 70% adherence to their (aerobic) workout regimen actually lost significant amounts of deep subcutaneous fat tissue.. speaking of adherence, there were no significant differences in adherence between the three training regimen; only the control treatment on the couch obviously had 100% adherence ;-) | Comment on FB!

References:

• Alberga, A. S., et al. "Effects of aerobic and resistance training on abdominal fat, apolipoproteins and high-sensitivity C-reactive protein in adolescents with obesity: the HEARTY randomized clinical trial." International journal of obesity (2005) (2015).
• Dansinger, Michael L., et al. "Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial." Jama 293.1 (2005): 43-53.
• Thompson, A., and J. Danesh. "Associations between apolipoprotein B, apolipoprotein AI, the apolipoprotein B/AI ratio and coronary heart disease: a literature‐based meta‐analysis of prospective studies." Journal of internal medicine 259.5 (2006): 481-492.
• Walldius, G., and I. Jungner. "The apoB/apoA‐I ratio: a strong, new risk factor for cardiovascular disease and a target for lipid‐lowering therapy–a review of the evidence." Journal of internal medicine 259.5 (2006): 493-519.

From BodyPump to HIIT, From Weight Lifting to Cardio - How Much Energy & Fat Do You Burn During & After Your Workouts and How do PWO Carbs or Protein Affect This

BodyPump is a fast paced workout with barbells. Light(er) weights, high reps, loud music and a drill instructor... if you know one, you'll know all of these group based "resistance training" workouts.

Sunday and time for a brief review of the latest exercise-related publications. Today, I picked two studies that took a closer look at something I would never suggest you'd consider a primary measure of the quality of your training: The energy expenditure during and after your workouts.

While exercise and the exercise-induced increase in energy-expenditure is an important pillar of diet (+ exercise) induced weight loss. The dietary component is what makes you lose weight, while the exercise component is meant to (a) maximize the retention of lean muscle tissue and (b) improve your overall fitness and health. If you're just "working out to burn energy" you're destined to fail; not least because you will never be able to tell exactly how many kcals you've "left in the gym". And beware: Especially while dieting, it's usually much less than you think ;-)

Read more about exercise-related studies at the SuppVersity

Tri- or Multi-Set Training for Body Recomp.?

Alternating Squat & Blood Pressure - Productive?

Pre-Exhaustion Exhausts Your Growth Potential

Full ROM ➯ Full Gains - Form Counts!

Battle the Rope to Get Ripped & Strong

Study Indicates Cut the Volume Make the Gains!

• People overestimate the energetic demands of "intense" exercise (Berthiaume. 2015) - In view of the fact that everyone knows the (inaccurate) rule of thumb that says that the amount of energy (in kcal) you expend when you're jogging is roughly your body weight times 10 (it's actually rather body weight times 7, unless you're running really fast, by the way), it's not surprising that Berthiaume et al.'s latest study shows that their subjects, 40 healthy men and women (age: 31.7±5.8 years, body mass index [BMI]: 24±2.6 kg/m²), significantly overestimated the amount of energy they expended during a (perceived) "intense" BodyPump(TM) workout.
  

  

  Figure 1: Young, healthy BodyPump practitioners overestimate the energetic demands of this kind of equipment based group workouts by over 36% (Berthiaume. 2015).

  Instead of the 394.1±116 kcal, the subjects thought they'd burned, the scientists measurements yielded an average energy expenditure of only 250.3±67.8 kcal during the 60 minute workout. Now, that's not really a problem if do BodyPump, because you like group workouts like these. In view of the fact that the typical clientele of programs like these tends to charge the energy they expend during workouts against the energy from extra food they'd like to eat (BIG mistake, learn why), this may be problematic.
  

  

  Figure 2: Just a reminder: The energy expenditure (kcal per kg of body weight per hour) due to body weight exercises calculated based on oxygen uptake during the exercises (traditional) or during the rest periods has been shown to be rather under- than overestimated (Vezina. 2014 | read more)

  Now, you may remember the results of Vezina's 2014 study (see Figure 2 and previous article). In said paper they used a much more precise method to arrive at the actual energy expenditure. In Berthiaume's study, a simple SenseWear armband was used. That's not the "traditional calc." in Figure 2 that proved to be so unreliable in Vezina's study, but it may still suffer from the same shortcomings when it comes to measuring anaerobic vs. aerobic energy expenditure. It would thus be prudent to be at least somewhat skeptical of the exactness of Berthiaume's results.
• Exercise type and post-workout supplementation influence post-exercise resting energy expenditure and respiratory exchange ratio (Wingfield. 2015) - I know, I have written about EPOC, which is actually nothing else than the total post-exercise energy expenditure in relation to the respiratory exchange ratio, repeatedly. There is a reason, though, that the latest study from the University of North Carolina still made it into the SuppVersity news: It compared six exercise sessions, consisting of three exercise modalities and two acute nutritional interventions - that's extraordinary, for sure.
  • AEE - aerobic endurance exercise - 30-min on the treadmill at 45% to 55% of the heart rate reserve), high-intensity interval running 
  • HIIT - ten rounds of a 60-s treadmill run at 85% to 95% HRR with a 60-s passive rest period), and 
  • HIRT - high-intensity resistance training consisting of leg presses and bench presses, lunges, shoulder presses, biceps curls, and triceps extensions using free weights for three sets of 6RM to 8RM followed by a 20- to 30-s rest for each set of a given exercise and 2.5 min between each exercise 
  • CHO and PRO (25 g of CHO (maltodextrin) or PRO (whey isolate) mixed with 6 oz of water in an opaque bottle. 
  With its s randomized, crossover, double-blind design, the study is also pretty well-powered, even though it had only twenty female, recreationally active participants (mean ± SD; age 24.6 ± 3.9 years; height 164.4 ± 6.6 cm; weight 62.7 ± 6.6 kg).
  

  

  Figure 3: Overview of the study design (Wingfield. 2015).

  Next to the post-exercise resting energy expenditure (REE) and respiratory rate (RER), which were analyzed via indirect calorimetry at baseline, immediately post (IP), 30 minutes (30 min) post, and 60 minutes (60 min) post exercise, the scientists obtained salivary samples, as well (both didn't change sign.). The latter were used to determine estradiol-β-17 and cortisol levels before the workouts. To exclude any influence of dietary changes, the subjects were asked to eat diets similar to those they had consumed when they wrote their 3-day food logs at the beginning of the study. Practically speaking, this meant that, on average, subjects ingested 2,078.7 ± 679.9 kcal, 253.7 ± 97.6 g CHO (approximately 48.8% CHO), 84.3 ± 29.9 g PRO (approximately 16.2% PRO), and 80.9 ± 36.7 g of fat (approximately 35.0% fat) per day.
  

  

  Figure 4: Only the HIIT modality yielded sign. inter-group differences as far as the resting energy expenditure is concerned. Even those were very transient, though, and disappeared 30 min after the workout (Wingfield. 2015).

  Interestingly, a statistical significant effect for the resting energy expenditure (REE) was observed only in the HIIT, yet not in the HIRT trial (Figure 4, A). This is a result you may not have expected based on the assumption that any form of intense activity (like resistance training in this case) should have some sort of "afterburn" effect.

Cortisol is not your enemy - at least in the short run: As expected the hardest workout, the HIIT workout, produced the most significant increase in cortisol. The change was still not statistically significant, but I decided to mention it anyway, in order to take the chance and remind you of the fact that cortisol is a glucocorticoid that will not just gnaw away your muscles (it does so if it's chronically elevated), but is also involved in a host of beneficial processes including acute increases in performance and the facilitation of body fat loss (learn more).

• What is less surprising is the relatively small, but "significant" (statistically, only!) increase in REE in response to protein vs. carbohydrate (Figure 4, B). So, protein is thermogenic even after a workout. Unfortunately, the increase in energy expenditure and the increase in fatty oxidation as signified by the reduced respiratory exchange ratio in Figure 5 B are way too small to be of any practical relevance.
  

  

  Figure 5: Effect of exercise modality and CHO vs. PRO supplement on the respiratory exchange ratio (RER); lower values indicate greater fat and lower carbohydrate oxidation (Wingfield. 2015).

  Eventually, the same can be said of the decrease in RER (=increase in fatty oxidation) in response to the HIIT and the increase in RER (=decrease in fatty acid oxidation) in response to the HIRT regimen. Both are statistically significant and look large enough to be relevant. When all is said and done, it does yet not really matter if you burn fat directly or glucose first. Whether you lose or gain body fat is after all a matter of the total energy balance over days and weeks, and not the fatty acid oxidation during and 60 minutes after your workouts.

So, what did we learn today? I guess the most important message is that even if it would make sense to charge the energy you expend at the gym against the amount of energy you consume in form of foods, you would fail miserably, because your estimation of how many kcals you've actually "left at the gym" are going to be hilariously inaccurate.

Five Good Reasons Why At Least 50% of Your 2015 'Cardio' Training Should Be High Intensity Interval Training (HIIT) | more

Against that background the results of the Wingfield study are still interesting, but of highly questionable practical value. Your decision whether you do steady state medium intensity cardio, resistance training or high intensity interval training should always be based on your training goals, not the energetic demands of the workouts. In that, fitter individuals (like yourself?) will see better results with high intensity interval training than classic cardio - assuming their training goal are increases in cardiovascular fitness. To maintain the fitness you have, steady state cardio can obviously still be an option; and weight training + optional protein supplements are the perfect choice for anyone who's interested in being and looking fit | Comment!

References:

• Berthiaume, M. P., et al. "Energy expenditure during the group exercise course BodypumpTM in young healthy individuals." The Journal of sports medicine and physical fitness 55.6 (2015): 563.
• Vezina, Jesse W., et al. "An Examination of the Differences Between Two Methods of Estimating Energy Expenditure in Resistance Training Activities." Journal of strength and conditioning research/National Strength & Conditioning Association (2014).
• Wingfield, et al. "The acute effect of exercise modality and nutrition manipulations on post-exercise resting energy expenditure and respiratory exchange ratio in women: a randomized trial." Sports Med Open. (2015)

How Much Fat Will You Gain in the Next 6 Months? Your Response to Overfeeding, Low Protein Intakes & Fasting May Tell You If, Yet not How Much Weight You'll Gain

If you oxidize the CHOs from this meal, instead of storing it as glycogen, that's bad news for ability to maintain your body weight over the next 6-months & beyond 

You will know (and maybe hate) them, people who are eating whatever they want, whenever they want while still being not exactly shredded, but at least very lean. What do all these people who have an extremely easy time keeping their weight stable in common?

A recent study from the Phoenix Epidemiology and Clinical Research Branch at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at the "glorious" National Institutes of Health (NIH) suggests that it may relate to the way they respond to fasting and overfeeding on high carb, low protein and eucaloric diets.

I have no idea why the scientists did not modify the protein intake during overfeeding

Are You Protein Wheysting?

5x More Than the FDA Allows!

More Protein ≠ More Satiety

Protein: Food or Supplement?

Protein Timing DOES Matter!

Less Fat, More Muscle!

It is by no means news that there is a considerable inter-individual variation in the energy cost of weight gain. Some people gain weight on a caloric surplus of only 10kcal/day, while others stash away hundreds of extra kcals without gaining a single pound of body fat (these figures have only illustrative values and are not meant to be "exact").

"In a prior cross-sectional study, the increase in energy expenditure (EE) with overfeeding and the decrease with fasting were found to be correlated in a small group of 14 male subjects (Weyer. 2011). Our group has previously shown that the EE response to overfeeding varies considerably among individuals but is consistent and reproducible within individuals. This individual contribution explains more of the observed variability in the EE changes with overfeeding than changes to the macronutrient content of the diet (Thearle. 2013). These studies seem to indicate that phenotypic differences may exist in the EE responses to fasting or overfeeding that may affect susceptibility to weight gain. As overeating or caloric restriction are necessary to alter weight, perturbations in energy balance may be needed to uncover responses that signify an energy conserving physiology versus a physiology that is better able to resist weight gain" (Schlögl. 2015).

In their latest study, Schlögl and colleagues extend their previous findings by addressing the question of whether this inter-individual variation in EE changes relates to future weight change. Or, to put it simply: They tried to answer the question

"Will your acute reaction to 24h overfeeding on different diets predict if you can maintain your weight over the next 6 months, or not?"

To answer the question, the 24-h EE during energy balance during fasting and four different overfeeding diets with 200% energy requirements was measured in a metabolic chamber in 37 subjects with normal glucose regulation while they resided in the clinical research unit of the NIH. Each of the diets was administered for exactly 24h with 3-day washouts in-between (breakfast at 07:00, entry into the calorimeter one hour later; further meals were provided inside the calorimeter at 11:00, 16:00, and 19:00 through a two-door airlock):

• a eucaloric reference diet which was 80% of the weight maintaining diet to account for the reduced energy expenditure due to being confined to the metabolic chamber that contained 50% carbohydrates, 30% fats, and 20% proteins
• a fasting trial (FST) in which the subjects sat in the metabolic chamber fasted
• a low-protein diet (LPF) with 51% carbohydrate, 46% fat, 3% protein
• a standard overfeeding diet (SOF) with 50% carbohydrate, 30% fat, 20% protein
• a high-fat, normal-protein overfeeding diet (FNP) with 20% carbohydrate, 60% fat, 20% protein
• a high-carbohydrate, normal-protein overfeeding diet (CNP) with 75% carbohydrate, 5% fat and 20% protein

To be able to assess the long-term weight gain, all participants returned for follow-up visit to the NIH headquarter 6-months after the initial measures.

Let me highlight the most surprising result in advance: It is really surprising that those with the largest increase in energy expenditure in response to (high carb) overfeeding gained the most amount of weight. Traditionally, we have thought that all that matters was a significant increase in energy expenditure in response to overfeeding that would allow "hard gainers" to simply burn through the extra calories.

On that occasion, their body weight and composition (DXA | unfortunately, the body fat level was not analyzed seperately) was measured and the change in body weight was correlated with (a) the decrease in 24-h EE during fasting and (b) the increase with the different overfeeding protocols.

Figure 1: 24h energy expression expressed relative to eucaloric reference diet (Schlögl. 2015)

The results of the scientists' correlation analysis were surprisingly unambiguous: A larger reduction in EE during fasting, a smaller EE response to low-protein overfeeding and a larger response to high-carbohydrate overfeeding all correlated with weight gain.

Figure 2: Sign. correlations between change in 24-EE during overfeeding / fasting and weight gain (Schlögl. 2015).

If you take a closer look at the correlations (r-values) and their significance in Figure 2 you will realize that all of them are statistically significant . In other words, there is a significant link between an increased risk of gaining weight in the next 6 months and

• a higher decrease in energy expenditure during fasting (Figure 2; A | this should remind you of the thrifty phenotype theory, cf. Wells. 2011)
• a smaller increase in energy expenditure during low protein dieting (Figure 2; B)
• a higher increase in energy expenditure during carbohydrate overfeeding (Figure 2; C)
• a higher higher reliance on fat during fasting (Figure 2; D)

Since the association of the fasting EE response with weight change was not independent from that of low-protein in a multivariate model, there are thus two independent propensities associated with weight gain (1) the very "effective" conservation of energy during caloric and protein deprivation, and (2) the wasteful handling of large amounts of carbohydrates - of these, at least the latter comes as a surprise, doesn't it?

Ha? That's crazy: While finding #1 is neither news nor surprising, it seems very awkward that a large reliance on carbohydrates during fasting and the presence of an increase in energy expenditure during carbohydrate overfeeding correlate with increased weight gain over the next 6 months. I have to admit: I expected the exact opposite.

The correlations observed in the study at hand do not change the previously discussed effects of overfeeding on different macronutrients | more

As Schlögl, et al. point out it is thus "not so much the response to caloric restriction, but rather the response to protein restriction, that defines a “thrifty” phenotype" (Schlögl. 2015). Schlögl et al. also offer an interesting explanation to the counter-intuitive link between increased respiratory quotients and thus increased carbohydrate oxidation and reduced fat oxidation during 24h of fasting which the authors attribute to the "naturally lean" individuals ability to store and thus subsequently more glucose in / from larger glycogen stores. This hypothesis is in line with previous studies that link an increased oxidation vs. storage (as glycogen) of carbohydrate with increased food intakes and weight gain (Pannacciulli. 2007; Zurlo. 1990).

Obviously, this observation leads us right to the one and only way to turn a "thrifty" into a "non-thrifty" (or at least less thrifty) phenotype: Exercise! Exercise increases the amount of muscle to store and the amount of glucose that can be stored on a per kg of lean muscle mass basis. So, if there's a way to turn an "easy-" into a "hard-gainer" it's by building muscle | Comment on Facebook!

References:

• Pannacciulli, Nicola, et al. "The 24-h carbohydrate oxidation rate in a human respiratory chamber predicts ad libitum food intake." The American journal of clinical nutrition 86.3 (2007): 625-632.
• Schlögl, Mathias, et al. "Energy expenditure responses to fasting and overfeeding identify phenotypes associated with weight change." Diabetes (2015): db150382.
• Thearle, Marie S., et al. "Extent and determinants of thermogenic responses to 24 hours of fasting, energy balance, and five different overfeeding diets in humans." The Journal of Clinical Endocrinology & Metabolism 98.7 (2013): 2791-2799.
• Wells, Jonathan CK. "The thrifty phenotype: An adaptation in growth or metabolism?." American Journal of Human Biology 23.1 (2011): 65-75.
• Weyer, C., et al. "Changes in energy metabolism in response to 48 h of overfeeding and fasting in Caucasians and Pima Indians." International journal of obesity and related metabolic disorders: journal of the International Association for the Study of Obesity 25.5 (2001): 593-600.
• Zurlo, Francesco, et al. "Low ratio of fat to carbohydrate oxidation as predictor of weight gain: study of 24-h RQ." American Journal of Physiology-Endocrinology And Metabolism 259.5 (1990): E650-E657.