Well, that's good because it leaves more room for a brief preview of the studies I am about to discuss in today's third serving of the SuppVersity ISSN Research Review 2015 - studies that are all related (in one way or another) to increased protein intake. Either in overweight or obese people, for whom higher protein meals increase the post-prandial increase of the "satiety hormone" GLP-1, or in vegans, vegetarians and everyone else who wants to make the most of his vegetable protein sources (pea and rice protein, to be precise) by adding digestive enzymes to the mix, or - last but not least - gymrats who ramp up their protein intake from 2.3 to 3.8 g/kg body weight to see even more pronounced improvements in body composition.
- High protein, high GLP-1, ... highly beneficial? As a SuppVersity reader you are aware of the far-reaching metabolic effects of GLP-1 on appetite (suppression | Näslund. 1999), glucose and fat metabolism, as well as thermogenesis (Lejeune. 2006). Against that background, you will know that the small, but statistically significant increase in GLP-1 Franklin et al. (2015) observed in their latest study which compared the effects of a high protein and high mono-unsaturated fat meal on the well-known incretin hormone may have significant long-term effects even though the blood glucose levels of the study's twenty-four overweight or obese participants (male/female: 12/12; age: 38.7 ± 15.3 (mean ± standard deviation) years; BMI: 31.6 ± 4.0kg/m²), who consumed isocaloric meals containing either 35.2% energy from fat and 20.7% from monounsaturated fat (HMF meal) or 31.9% energy from protein (HP meal), did not trigger differences in post-prandial glucose levels at 30, 60, 120, and 180 min.
Figure 1: Levels of active GLP-1 in response to high protein (HP) or high MUFA (HMF) meals (Franklin. 2015).
If that sounds like you, using the high(er) protein meals in conjunction with an energy restricted diet to lose weight and thus to improve your insulin sensitivity can obviously still be beneficial. Without a planned, reasonable caloric deficit, however, high(er) protein intakes alone are probably not going to "cut it" (all puns intended).
|Even if weight loss is the goal, training fasted and thus hungry does not appear to provide significant benefits. Learn more about this longstanding myth and the reality in my write-up of Schoenfeld et al's seminal paper on fasted cardio and fat loss. A paper that finally had a long-standing and die-hard fat loss myth tumble.|
- Pimp my plant protein - digestive enzymes can do the trick! Despite the fact that pea and other protein powders have become widely (and cheaply) available over the past years, vegan and vegetarian athletes and gymrats are still having a harder time satisfying their protein requirements than their omnivore competition or gym-buddies. Against that background and in view of the fact that more and more athletes are "going vegan" or at least vegetarian, the latest study by Julie Minevich (2015) and colleagues from the University of Tampa and the formulators, manufacturers and vendors of digestive enzymes and respective supplements from Chemi-Source and Increnovo LLC, was in fact published quite timely. A study that was designed...
"to investigate if co-ingestion of a plant protein specific digestive enzyme blend (Digest-All® VP, a proprietary enzyme blend consisting of protease 6.0, protease 4.5, peptidase, bromelain and alpha-galactosidase, Chemi-Source, Inc., Oceanside, CA) can reduce the significant differences in amino acid appearance in the blood between plant and animal proteins" (Minevich. 2015).To this ends, 11 resistance-trained male subjects (age: 21.4 ± 1.5 years, body weight: 82.5 ± 3.9kg, height: 177.3cm ± 6.1cm | average training status of 2.3 years ± 1.9 years) were randomly assigned to receive either 60 g of whey protein concentrate, or the same amount of protein in form of a 70:30 blend of pea and rice protein concentrates (Veg), either alone or alonside the enzyme blend Digest-All® VP in a double-blind, crossover study. All supplements were provided on an empty stomach after a 12 hour overnight fast. The three testing sessions, in which blood was drawn immediately prior to, and at 30 minutes, 1, 2, 3, and 4 hours following consumption of the supplements, were separated by a washout period of 7 days.
Figure 2: Time to achieve peak amino acid levels and total amount of amino acids that made it to the blood stream with whey protein, the pea + rice mix and the pea + rice mix w/ digestive enzymes (Minevich. 2015).
If you also take into account that the digestive enzyme blend brought the area under the EAA curve (see Figure 2) and the peak amino acid levels (not shown in Figure 2) of the vegetable protein blend up to the same level as it was observed with whey protein, it would seem as if the study would provide the missing evidence of the usefulness of proteases and co. for people who want to make the absolute most of their vegetable protein supplements - what is missing, obviously, is data that would allow us to quantify the downstream effects on muscle gains and other practically relevant study outcomes.
- High protein + training = WIN?! You will certainly remember the impressive results of Antonio et al.'s 2014 study on the effects of a 4.4g/kg protein diet on the body composition healthy resistance-trained men and women (learn more). Right after said study had been published the authors promised a follow up that would combine a similarly high protein intake with a controlled exercise intervention and... voila! The first results of this study were presented at this year's ISSN meeting.
For the corresponding experiment, Ellerbroek et al. recruited forty-eight healthy resistance-trained men and women in their early twenties. who consumed either 2.3g/kg body weight per day (NP) or 3.4g/kg body weight per day (HP) of dietary protein during the treatment period. Moreover, all subjects participated in a split-routine, body part heavy resistance-training program. Training and diet (everyday) logs were kept by each subject.
|Learn everything about the previous study.|
- As the scientists point out in the results section of the abstract, their two-time point (Pre, Post) by two-group (NP, HP) repeated-measures analysis of variance (ANOVA) showed (a) significant time by group (p ≤ 0.05) changes in body weight with weight gains and loss in the normal and high protein groups, respectively (1.3 ± 1.3 kg NP, -0.7 ± 4.0 HP), as well as reductions in total and relative body fat in both groups (-0.3 ± 2.2 kg NP, -1.7 ± 2.3 HP), and % BF (-0.7 ± 2.8 NP, -2.4 ± 2.9 HP) - both as you can see in Figure 3 with significant advantages for the HP group.
Figure 3: Changes in body weight, fat and fat free mass in the normal and high protein groups during the diet + training intervention; mind the error bars = high inter-individual differences (Ellerbroek. 2015).
- Detzel, Christopher J., et al. "Functional animal proteins activate mTOR and bind pro-inflammatory compounds." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P35.
- Ellerbroek, Anya, et al. "The effects of heavy resistance training and a high protein diet (3.4 g/kg/d) on body composition, exercise performance and indices of health in resistance-trained individuals-a follow-up investigation." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P37.
- Franklin, Brian, et al. "The effect of meal composition on postprandial glucagon-like peptide-1 response in overweight/obese participants." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P12.
- Galvan, E., et al. "Effects of 28 days of two creatine nitrate based dietary supplements on bench press power in recreationally active males." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P17.
- Jäger, Ralf, et al. "Analysis of the efficacy, safety, and regulatory status of novel forms of creatine." Amino Acids 40.5 (2011): 1369-1383.
- Lejeune, Manuela PGM, et al. "Ghrelin and glucagon-like peptide 1 concentrations, 24-h satiety, and energy and substrate metabolism during a high-protein diet and measured in a respiration chamber." The American journal of clinical nutrition 83.1 (2006): 89-94.
- Näslund, E., et al. "Energy intake and appetite are suppressed by glucagon-like peptide-1 (GLP-1) in obese men." International journal of obesity 23.3 (1999): 304-311.
- Nystrom, M. G., et al. "Nutrient timing habits of Division I NCAA athletes." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P33.
- Minevich, Julie, et al. "Digestive enzymes reduce quality differences between plant and animal proteins: a double-blind crossover study." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P26.