Sufficient Sleep & 6 Cups of Green Tea - Proven Ways to Increase Your Energy Expenditure & Conserve Your Resting Metabolic Rate While Dieting | Part II of A Multipart Series

I suppose you will have known that sleep hygiene & green tea help, but did you know the exact numbers when it comes to their effects on your resting energy expenditure, as well? No? In this case, today's SuppVersity article is for you!

In the first installment of this new SuppVersity series, you've learned about the pro-metabolic effects of eating less frequent large(er) meals and the ability of caffeine to boost resting energy expenditure and fatty acid oxidation. Today, we're going to take a look at the effects of sleep and green tea on the amount of energy your body consumes in a given 24h window.

In 2011, Christian Benedict and colleagues conducted an interesting study. The German scientists examined the resting energy expenditure of 14 normal-weight male subjects on two occasions during a regular 24-h sleep-wake cycle (including 8 h of nocturnal sleep) and a 24-h period of continuous wakefulness in a balanced cross-over study.

Not living in tune with your circadian rhythm is a reliable way to become obese!

Sunlight, Bluelight, Backlight and Your Clock

Sunlight a La Carte: "Hack" Your Rhythm

Breaking the Fast to Synchronize the Clock

Fasting (Re-)Sets the Peripheral Clock

Vitamin A & Caffeine Set the Clock

Pre-Workout Supps Could Ruin Your Sleep

On the morning after regular sleep and total sleep deprivation, resting and postprandial energy expenditures were assessed by indirect calorimetry, and the free choice food intake from an opulent buffet was tested in the late afternoon at the end of the experiment.

In addition to energy expenditure and intake the scientists also checked, whether the lack of sleep would affect the concentrations of ghrelin, leptin, norepinephrine, cortisol, thyreotropin, glucose and insulin; and they did so repeatedly over the course of the whole 24 study period.

Figure 1: Sleep loss reduced the morning energy expenditure in humans. After a night of regular sleep (black bars) and a night of continuous wakefulness (white bars), metabolic rates were measured by indirect calorimetry in healthy young men under resting conditions [resting metabolic rate (RMR)] between 0745 and 0815 and after the consumption of a liquid standard breakfast (600 mL of a vanilla-flavored energy drink that contained 3.8 MJ | Benedict. 2011)

As you can easily see, Benedict et al. observed highly significant decreases in energy expenditure in the sleep deprivation condition (Figure 1, open bars). Similar results (-147kcal/day | ca. -10%) have been observed by Nedeltcheva et al. (2010) who were also able to confirm that "sleep curtailment decreased the fraction of weight lost as fat by 55% (1.4 vs. 0.6 kg with 8.5 vs. 5.5-h sleep opportunity, P=0.043) and increased the loss of fat-free body mass by 60% (1.5 vs. 2.4 kg, P=0.002)" in a long(er) term human study.

Figure 2: 10% reduction in insulin sensitivity after less than one week of sleep deprivation is bad news, even if there were two outliers where the insulin sensitivity increased - they are the literal "exceptions that confirm the rule" (Buxton. 2010)

Reduced energy expenditure + increased intake: That's the perfect recipe for becoming obese and ruining your diet efforts; and it is the consequence of sleep deprivation, which increases energy intake in general and your propensity to grab unhealthy snacks instead of whole foods to satisfy your cravings (Nedeltcheva. 2009). In conjunction with the rapid onset of insulin resistance (-10% glucose clearance on oral GGT after less than one week in Buxton. 2010) and up to 52% reductions in overnight fatty acid oxidation (Klingenberg. 2012), this should be reason enough to ensure that you're getting your 6.5-8h of quality sleep every night... and this goes even if studies show population-specific differences in the extend and significance of the effects.

Benedict et al. also observed increased wake-up ghrelin levels (➭ increased hunger), unstable glucose and increased stress (norepinephrine) levels during the night (➭ sugar cravings, while staying awake), as well as paradoxically increased thyretropin levels (➭ should increase the production of thyroid hormone). Ndeltcheva et al. report changes in metabolically relevant hormones, as well - statistically significant were yet only the increases in acetylated ghrelin and the drop in epinpephrine at the end of the intervention. Effects on thyroid hormone concentrations as they have also been observed and outlined by Baumgartner et al. (1993) and Pereira et al. (2014), respectively, have not been observed by either of the scientists.

Three to six cups of green tea and a good nights sleep - that's all?!

Let's leave the sleep issue now and get to #2 on today's list of RMR boosters: Green tea. There is surprisingly little evidence with respect to the beneficial or detrimental effects of green tea on sleep. What we do know, though, is that theanine, an amino acid that can be found in all sorts of teas, appears to promote healthy sleep in people who are at a particularly high risk of not getting their daily dose of quality sleep due to ADHD (Lyon. 2011) and people who have problems to relax (Mason. 2001; Unno, 2013).

No, theanine is not green tea specific! In fact, Keenan et al. found only three years ago that "[c]ontrary to previous research, a standard (200 ml) cup of black tea was found to contain the most l-theanine (24.2 ± 5.7 mg) while a cup of green tea contained the least (7.9 ± 3.8 mg)." (Keenan. 2011). If you want to calm yourself down, you're thus better off with a long-brewed cup of black tea.

Now theanine has also been found to "partially counteracts caffeine-induced sleep disturbances" (Jang. 2012). Accordingly, you may argue that it's probably not that much of a problem if you are consuming green tea relatively close to going to bed. Personally, I would yet not recommend taking the risk that the caffeine messes with your sleep (learn more).

The reason green tea made it into today's issue of the "natural metabolism boosters"-series should be obvious: There are dozens of studies showing increases in RMR, even when the guys or, as in the case of a 2010 study by Stendell-Hollis, the girls in the placebo group experienced a diet-induced reduction in resting metabolic rate.

Figure 3: Changes in RMR in cancer survivors on lifestyle program with or without 960 mL of green tea per day with, on average, 236 mg total catechins (Stendell-Hollis. 2010)

The number of studies, where this difference reached statistical significance, on the other hand, is small. In the previously cited study by Stendell-Hollis, for example the total difference was 18.09 kilocalories per day, which would be a joke, even if the standard deviations were not >200kcal/day and the result thus statistically 100% non significant.

Figure 4: Energy expenditure (EE) during the 125 h chamber stay plotted against the five different treatments. Inter-group differences in % (Gregersen. 2009).

Caffeine + EGCG make a powerful team, but... In a 2009 studies, scientists from the University of Kopenhagen found that EGCG, the best known of the dozen of green tea catechins is an excellent synergist to caffeine, my recommendation from the last installment of this series and increases. The data Gregerson et al. present in the May issue of the British Journal of Nutrition does yet also show that (a) the other catechins work as well, and (b) caffeine, not EGCG is the #1 metabolic energizer (150mg caffeine alone ➭ 1.7% increase in energy expenditure vs. caffeine + EGCG ➭ 2.3% increase in energy expenditure).

It is thus questionable, whether it makes sense to buy caffeine-free green-tea extracts, unless you want to take an additional dose right before bed and plan to combine the product with coffee or caffeine tabs in the AM and early PM.

As the data Hursel et al. present in one of the most comprehensive reviews of the effects of green tea on energy expenditure suggests, the extent of the effects is highly variable and depends on dosing and subject characteristics (specifally obese vs. non-obese subjects with greater efficiacy of caffeine + GTE in lean sujects / this went so far that in Boschmann (2011) EGCG alone had even zero effect in obese men; also, from previous studies: greater effects in Asians vs. Caucasians and smaller effects in people consuming >300mg/day of caffeine habitually; cf. Hursel. 2009).

Figure 5: Modified overview of the changes in energy expenditure (left) and fatty acid oxidation (right) from Hursel et al. (2008) - a brief glance at the data from the circled trials indicates: there is a benefit from adding catechins!

If we discard this important fact and simple average the data from the studies Hursel et al. reviewed in 2008, the mean increase in energy expenditure over 24 h for green tea catechins + caffeine would equal 428.0 kJ/day. That's 102.3kcal/day (+4.7%) and thus lower, albeit not significantly lower than the average of the caffeine only trials that were included in the same review.

Toxicity Warning! Do yourself a favor and don't buy lead, chromium and cadmium laden Chinese green tea. I wrote about this problem back in May and I don't think that the levels have improved in the mean time (learn more). In the end, even the previously reported reductions in testosterone in response to green tea consumption could be related to unwanted heavy metals.

Figure 6: Green tea does more to help you lose weight than to increase your energy expenditure (Rains. 2011)

If we look at it study by study, however, it turns out that the circled trials in Figure 5 proof an additive effect of green tea catechins that goes beyond that of caffeine. It may be smaller than the hype around green tea supps suggests, but it is there.

In conjunction with the other established benefits of green tea catechins, as they were highlighted by Rains et al. in a 2011 review (see Figure 6), the addition of green tea extracts to your regimen as a means to increase and maintain your resting energy expenditure appears warranted, specifically if you're suffering from high grade inflammation, as well.

There is yet more to the data in Figure 5, specifically to the data that relate to a study by Sonia Bérubé-Parent, Catherine Pelletier, Jean Doré and Angelo Tremblay (check out the data from the Bérubé-Parent study in isolation). Their study does after all answer the question that may be preying on your heads, now: Yes, there is an increase in energy expenditure with increasing EGCG levels, but this increase is minimal and the use of more than 250mg/day appears futile based on the data Bérubé-Parent et al. collected.

Figure 7: Estimated catechin (large box) and caffeine (small box) intake form 6 cups of fruit, green or black teas as they are commonly sold in the United Kingdom (Khokhar. 2002)

Bottom line: The improvements in energy expenditure in response to green tea and sleep may not be as pronounced as those in response to the agents / habits in the last installment of this series (go back and learn more).

And still, the use of green tea supplements and, even more so, sleep hygiene (regular sleeping patterns, 6-8h of sleep every night, sleeping in a quiet, dark environment, no screen use in the late PM, etc.) have multilayered metabolic effects that will help you lose weight and stay lean and will thus work synergistically with caffeine and eating larger meals less frequently.

In that, I would consider sleep hygiene, the basics of which I outlined in the circadian rhythm series. The consumption of 6 small cups (100ml) of green tea (this will deliver ~260mg of catechins including approx. 100-120mg of EGCG, six regular cups would get you to the dosage at which Bérubé-Parent et al. observed a ceiling effect | Khokhar. 2002) or a similar amount of catechins from supplements, on the other hand, that is commonly overestimated | Comment on Facebook!

References:

• Baumgartner, Andreas, et al. "Influence of partial sleep deprivation on the secretion of thyrotropin, thyroid hormones, growth hormone, prolactin, luteinizing hormone, follicle stimulating hormone, and estradiol in healthy young women." Psychiatry research 48.2 (1993): 153-178.
• Benedict, Christian, et al. "Acute sleep deprivation reduces energy expenditure in healthy men." The American journal of clinical nutrition 93.6 (2011): 1229-1236.
• Bérubé-Parent, Sonia, et al. "Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men." British Journal of Nutrition 94.03 (2005): 432-436.
• Boschmann, Michael, and Frank Thielecke. "The effects of epigallocatechin-3-gallate on thermogenesis and fat oxidation in obese men: a pilot study." Journal of the American College of Nutrition 26.4 (2007): 389S-395S.
• Buxton, Orfeu M., et al. "Sleep restriction for 1 week reduces insulin sensitivity in healthy men." Diabetes 59.9 (2010): 2126-2133.
• Gregersen, Nikolaj T., et al. "Effect of moderate intakes of different tea catechins and caffeine on acute measures of energy metabolism under sedentary conditions." British journal of nutrition 102.08 (2009): 1187-1194. 
• Hursel, R., W. Viechtbauer, and M. S. Westerterp-Plantenga. "The effects of green tea on weight loss and weight maintenance: a meta-analysis." International journal of obesity 33.9 (2009): 956-961. 
• Hursel, R., et al. "The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta‐analysis." obesity reviews 12.7 (2011): e573-e581.
• Jang, Hwan-Soo, et al. "L-theanine partially counteracts caffeine-induced sleep disturbances in rats." Pharmacology Biochemistry and Behavior 101.2 (2012): 217-221.
• Lyon, Michael R., Mahendra P. Kapoor, and Lekh R. Juneja. "The effects of L-theanine (Suntheanine) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial." Altern Med Rev 16.4 (2011): 348-354. 
• Keenan, Emma K., et al. "How much theanine in a cup of tea? Effects of tea type and method of preparation." Food chemistry 125.2 (2011): 588-594. 
• Khokhar, S., and S. G. M. Magnusdottir. "Total phenol, catechin, and caffeine contents of teas commonly consumed in the United Kingdom." Journal of Agricultural and Food Chemistry 50.3 (2002): 565-570.
• Klingenberg, Lars, et al. "Short sleep duration and its association with energy metabolism." Obesity Reviews 13.7 (2012): 565-577.
• Mason, Russ. "200 mg of Zen: L-theanine boosts alpha waves, promotes alert relaxation." Alternative & Complementary Therapies 7.2 (2001): 91-95.
• Nedeltcheva, Arlet V., et al. "Sleep curtailment is accompanied by increased intake of calories from snacks." The American journal of clinical nutrition 89.1 (2009): 126-133.
• Nedeltcheva, Arlet V., et al. "Insufficient sleep undermines dietary efforts to reduce adiposity." Annals of internal medicine 153.7 (2010): 435-441.
• Pereira Jr, José Carlos, and Mônica Levy Andersen. "The role of thyroid hormone in sleep deprivation." Medical hypotheses 82.3 (2014): 350-355. 
• Rains, Tia M., Sanjiv Agarwal, and Kevin C. Maki. "Antiobesity effects of green tea catechins: a mechanistic review." The Journal of nutritional biochemistry 22.1 (2011): 1-7.
• St-Onge, Marie-Pierre, et al. "Short sleep duration increases energy intakes but does not change energy expenditure in normal-weight individuals." The American journal of clinical nutrition 94.2 (2011): 410-416. 
• Stendell‐Hollis, Nicole R., et al. "Green tea improves metabolic biomarkers, not weight or body composition: a pilot study in overweight breast cancer survivors." Journal of human nutrition and dietetics 23.6 (2010): 590-600.
• Unno, Keiko, et al. "Anti-stress effect of theanine on students during pharmacy practice: Positive correlation among salivary α-amylase activity, trait anxiety and subjective stress." Pharmacology Biochemistry and Behavior 111 (2013): 128-135.