Does Increasing Your Meal Frequency Increase Your Metabolism?
At one time or another I am sure you have heard the recommendation to consume smaller meals throughout the day. By consuming smaller, more frequent meals it is supposed to speed up your metabolism, reduce your hunger and help you lose weight. Where bigger, less frequent meals put your body into starvation mode. This “starvation mode” slows down your metabolism, increases hunger and causes weight gain. Luckily, this isn't true. Could you imagine how fat America would be if you gained weight when you didn't eat? Just think about that for a second and let it sink in.
The starvation hypothesis came from the idea that if you don't eat your body will stop burning calories and store them for energy. Your body stored the calories as fat because it doesn't know when the next meal is coming. This may make sense on paper, but it is too narrow of a focus. The body doesn't operate on a per meal basis, if it did then fasting would slow down your metabolism, but the research doesn’t support that claim. A study done by the American Journal of Clinical Nutrition, found that individuals who fasted for 84 hours increased their resting energy expenditure. The scientists believe the increased metabolism was due to the increased norepinephrine levels i.e a mild stress response (1). This same process also occurs in high intensity exercise, and no one claims that exercise slows down your metabolism, right? (2)
The study above proves that the starvation hypothesis is a myth. Plus, our metabolism isn't influenced by the number of meals, it is influenced by the number of calories consumed. When you consume food your body requires energy to breakdown and digest it. Whether you eat three or six meals, if the calorie total is 2,000 calories than the metabolic effect from the food will be the same regardless of how many meals you eat. So now that we know starvation mode doesn’t exist if you skip a meal. Let’s take a look and see if there are any metabolic benefits to an increased meal frequency.
The studies below that show an increased meal frequency will not increase your metabolism enough for weight loss. The first study, Effects of Increased Meal Frequency on Fat Oxidation and Perceived Hunger, compared energy expenditure from three meals versus six meals over a three day period. The study found no difference in metabolism between the two groups. But the authors did hypothesize that an increased meal frequency could lead to increased hunger. (3) Granted, this is just one study so the results could be an outlier. However, the authors from a meta analysis of 15 studies on the effects of meal frequency found no significant benefit from an increased meal frequency when calories were matched.(4)
In previous posts I have written in length about the benefits of less frequent meals and the benefits that can come from fasting and time restricted eating. It is important to realize that the majority of these benefits are coming from a calorie restricted diet. A smaller eating window forces you to eat fewer meals which then leads to less calories consumed. But if you can eat the same amount of calories with more frequent smaller meals then you will obtain the same benefits of calorie restriction. Granted, in my experience as a personal trainer I have found fewer meals to be much for effective for weight loss versus more meals, which is why I recommend my clients to eat only two to four meals a day. At the end of the day, the most important thing in your diet is going to be calories in versus calories out. Be it three meals or six meals, find what works for you and stick with it for a month.
Zauner C, Schneeweiss B, Kranz A, Madl C, Ratheiser K, Kramer L, Roth E, Schneider B, Lenz K. Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. Am J Clin Nutr. 2000 Jun;71(6):1511-5. PubMed PMID: 10837292.
Kon M, Nakagaki K, Ebi Y, Nishiyama T, Russell AP. Hormonal and metabolic responses to repeated cycling sprints under different hypoxic conditions. Growth Horm IGF Res. 2015 Jun;25(3):121-6. doi: 10.1016/j.ghir.2015.03.002. Epub 2015 Apr 12. PubMed PMID: 25900847.
Ohkawara, K., Cornier, M.-A., Kohrt, W. M., & Melanson, E. L. (2013). Effects of Increased Meal Frequency on Fat Oxidation and Perceived Hunger. Obesity (Silver Spring, Md.), 21(2), 336–343. http://doi.org/10.1002/oby.20032
Brad Jon Schoenfeld, Alan Albert Aragon, James W. Krieger; Effects of meal frequency on weight loss and body composition: a meta-analysis, Nutrition Reviews, Volume 73, Issue 2, 1 February 2015, Pages 69–82, https://doi.org/10.1093/nutrit/nuu017