Less Frequent Large(r) Meals & Caffeine - Proven Ways to Increase Your Energy Expenditure & Conserve Your Resting Metabolic Rate While Dieting | Part I of A Multipart Series

Whether you want to lose or gain weight, never forget to "Eat to live!"

To lose weight, you must create a negative energy balance.It is however unrealistic to expect your body not to do everything it can to conserve energy, when you've been eating 50% below maintenance for weeks (e.g. you need 2,000kcal, but eat only 1,000). Not to reduce your energy intake by more than 40% (for max. 2 weeks) and going with 20-25% if you plan to diet for 4-6 weeks would thus qualify as rule #1; a rule of which I can only say that I highly recommend you stick to it, because if you don't even the five tips below are not going to save your metabolism from crashing (learn more about the nine rules that can help avoiding metabolic shut-down).
Ah, and before I forget to mention it. If you don't control your dietary energy intake, chances that any of the following tricks (in that case magically) help you lose weight without the need to diet are anywhere between "slim" and "zero".

• Eat large meals less frequently: It may go against the longstanding recommendation, but due to the fact that meal size, not macro composition is the main determinant of the post-meal increase in thermogenic effect.

  Figure 1: Increase in metabolic rate above basal metabolic rate (BMR) (kJ/min) after ingestion of four different test meals by human subjects (Kinabo. 1999)

  And considering the fact that the latter lasts for 5h+ (see Figure 1) the idea that you have to eat a small meal every hour "to stoke the furnace" is fundamentally flawed. No wonder, people all over the world are successfully using weight by intermittent fasting.

• You have to be careful, though, long arduous workouts during the fast or fasting for more than 12-16h could nullify the thermogenic benefit of being able to eat to satiety once or twice a day. And no! The Kinabo study is not a statistical outlier, it's just like a study with almost identical results by Tai et al. (1991) real vs. broscience which dictates that you "got to stock the furnace" - a practice of which the latest controlled studies show that is has "no significant effect on 24-h fat oxidation, but may increase hunger and the desire to eat." (Ohkawara. 2013)

• Use 4mg/kg caffeine per day - You will certainly have expected to see caffeine on the list of agents that help. Unfortunately, caffeine is significantly more effective for lean vs. overweight individuals. In a study from the Institute of Physiology at the University of Lausanne, David Bracco and colleagues were able to show that the thermogenic effect of caffeine coffee (4mg/kg body weight) was 35.6% more pronounced in the lean vs. obese female subjects (Bracco. 1995) - similar results have been reported by Belza et al. (2007), Hollands et al. (1981) increases of 15% in the two hours after the ingestion of caffeinated vs. decaffeinated coffee.
  

  Figure 2: Relative increase in resting metabolic rate, energy expenditure during exercise and sleep in lean and obese women in response to the ingestion of 4mg/kg of caffeine (vs. placebo | Bracco. 2014)

  In addition to the overall effect size, the data in Figure 2 does also indicate that an "over night" effect, as well as the increase in energy expenditure during workouts were likewise only observed in the lean, not in the obese women (since the lack of thermogenesis has been associated with decreased insulin sensitivity using 300-500mg of alpha lipoic acid, as I have suggested in a recent article, may ameliorate the reduction in postprandial thermogenesis).

• Now 4mg/kg may seem like quite a high dosage for some of you. In contrast to the usual SuppVersity mantra that "more won't help more", those 4mg caffeine per kg of body weight are yet well necessary. In a 1999 study from the University of Geneva, for example, the administration of only 50mg of caffeine had no effect on the resting energy expenditure of 10 healthy male volunteers (Dullo. 1999).
  
  

  Figure 3: Substrate utilization (mg/min) before (filled bars) and after (empty bars) the ingestion of a complex test meal with either coffee (4mg/kg caffeine) or decaffeinated coffee (Acheson. 1980).

  Furthermore, caffeine has also been shown to increase the thermic effects of a meal and to shift the fuel utilization towards fatty acids (Acheson. 1980; see Figure 3). The latter will not necessarily help you to burn more body fat, but it will spare liver and muscle glycogen, when you're dieting and reduce the chances that your liver resorts to amino acids from your musculature to cover the glucose requirements of your body.
  
  In conjunction with the net increase in energy expenditure Dullo et al. quantify in the range of 150 kcal in lean volunteers and 79 kcal as a response to the bi-hourly consumption of 100mg of caffeine in the post-obese subjects, there is little doubt that
  

  "Caffeine at commonly consumed doses can have a significant influence on energy balance and may promote thermogenesis in the treatment of obesity." (Dullo. 1989)

  Studies by Yoshida et al. support this notion and confirm that the addition of caffeine to the weight loss equation will be particularly effective in overweight individuals with reduced baseline metabolic rate (Yoshida. 1995) and more recent experimental data from the University of Maastricht confirms that high caffeine intakes are associated not just with increased weight loss through thermogenesis and fat oxidation, but also with reduced fat mass, and waist circumference in overweight and moderately obese subjects (Westerterp‐Plantenga. 2005).

References:

• Acheson, K. J., et al. "Caffeine and coffee: their influence on metabolic rate and substrate utilization in normal weight and obese individuals." The American journal of clinical nutrition 33.5 (1980): 989-997. 
• Bakuradze, Tamara, et al. "Four weeks coffee consumption affects energy intake, satiety regulation, body fat, and protects DNA integrity."Food Research International (2014).
• Bracco, David, et al. "Effects of caffeine on energy metabolism, heart rate, and methylxanthine metabolism in lean and obese women." American Journal of Physiology-Endocrinology and Metabolism 32.4 (1995): E671. 
• Dulloo, A. G., et al. "Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers." The American journal of clinical nutrition 49.1 (1989): 44-50.
• Dulloo, Abdul G., et al. "Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans." The American journal of clinical nutrition 70.6 (1999): 1040-1045.
• Hollands, Marjorie A., J. R. Arch, and M. A. Cawthorne. "A simple apparatus for comparative measurements of energy expenditure in human subjects: the thermic effect of caffeine." The American journal of clinical nutrition 34.10 (1981): 2291-2294.
• Jonee, Lilian, and George A. Bray. "The thermic effect of food and obesity: a critical review." Obesity research 5.6 (1997): 622-631.
• Kinabo, J. L., and J. V. G. A. Durnin. "Thermic effect of food in man: effect of meal composition, and energy content." British Journal of Nutrition 64.01 (1990): 37-44. Segal, Karen R., et al. "Thermic effect of food at rest, during exercise, and after exercise in lean and obese men of similar body weight." Journal of Clinical Investigation 76.3 (1985): 1107.
• McCarty, Mark F. "A chlorogenic acid-induced increase in GLP-1 production may mediate the impact of heavy coffee consumption on diabetes risk." Medical hypotheses 64.4 (2005): 848-853.
• Ohkawara, Kazunori, et al. "Effects of increased meal frequency on fat oxidation and perceived hunger." Obesity 21.2 (2013): 336-343.
• Segal, Karen R., et al. "Thermic effect of food at rest, during exercise, and after exercise in lean and obese men of similar body weight." Journal of Clinical Investigation 76.3 (1985): 1107.
• Tai, Mary M., Peter Castillo, and F. Xavier Pi-Sunyer. "Meal size and frequency: effect on the thermic effect of food." The American journal of clinical nutrition 54.5 (1991): 783-787. 
• Westerterp‐Plantenga, Margriet S., Manuela PGM Lejeune, and Eva MR Kovacs. "Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation." Obesity research 13.7 (2005): 1195-1204.
• Yoshida, T., et al. "Relationship between basal metabolic rate, thermogenic response to caffeine, and body weight loss following combined low calorie and exercise treatment in obese women." International journal of obesity and related metabolic disorders: journal of the International Association for the Study of Obesity 18.5 (1994): 345-350.