Nutrition

January 25, 2015


Are Frequent Meals Beneficial for Body Composition

Conventional wisdom states that eating small, frequent meals helps to optimize weight loss. In theory, eating frequently enhances a phenomenon called the thermic effect of food (TEF), which results in more energy expended after consumption of the meal. What’s more, some postulate that multiple meals spaced throughout the day prevents the body from going into “starvation mode,’ thereby keeping metabolism perpetually elevated.

There also is speculation that frequent feedings are beneficial for anabolism. This is based on the premise of a limit to how much protein can be used to maximize protein synthesis. It therefore follows that large boluses of protein result in extensive oxidation of amino acids, preventing their use in tissue building purposes.

Despite a seemingly logical rationale, the efficacy of consuming frequent meals to optimize body composition has not been well established in long-term studies. In an attempt to gain clarity on the topic, my lab recently carried out a meta-analysis where we pooled the data from all meal frequency studies. The analysis was a collaboration with my colleagues and frequent partners-in-science, James Krieger and Alan Aragon. Here’s the scoop…

What We Did
A thorough search of all English language journals was conducted for studies with the following inclusion criteria:
1. Randomized controlled trial
2. Compared unequal feeding frequencies of less than or equal to 3 meals a day with greater than 3 meals a day
3. Had a study duration of at least 2 weeks
4. Reported a pre- and post-intervention measure of body composition (body mass, body fat, lean mass)
5. Was carried out in human participants >18 years of age

A total of 15 studies were identified that met the criteria outlined and provided adequate data for analysis – several of these studies went back as far as the early 1960’s! The studies were individually coded and a randomly selected number of them were subsequently recoded to ensure accuracy. The coded studies were then pooled and statistically analyzed to determine what, if any, body composition differences existed between feeding frequencies.

What We Found
There was no effect of the number of daily meals on body mass (i.e. weight). Alternatively, initial analysis did show a positive association between feeding frequency and reductions in fat mass. Here’s the kicker: a sensitivity analysis showed that a single 2-week study by Iwao et al. highly affected results – when this study was removed from analysis, the effect of meal frequency was no longer significant. Similarly, body fat percent was initially shown to correlate with greater decreases in body fat percentage, but the results were highly affected by a single study by Arciero et al. whose removal rendered the results insignificant. There was a trend for greater increases in fat free mass with higher meal frequencies, but again the results were primarly attributed to the Iwao et al. study.

Commentary
Meal_Frequency
The results of our analysis do not support a tangible benefit to eating small frequent meals on body composition as long as daily caloric intake and macronutrient content is similar. The theory that a greater feeding frequency increases post-prandial thermogenesis is fundamentally flawed. As shown in the accompanying table, a typical meal results in a TEF of approximately 10%. Since the TEF is dependent on the number of calories consumed in the meal, the net thermic effect is the same for 3 versus 6 meals on a calorie-equated basis. There also is no evidence that the body goes into “starvation mode” when you go without food for more than a few hours as commonly claimed in fitness circles. I covered the research on this in a recent T-Nation article.

The studies in question lasted varying amounts of time and many used recall food diaries to assess caloric intake, which have been shown to lack accuracy in reporting. However, several studies were carried out in metabolic wards where every morsel of food and every step of activity was carefully monitored – these studies showed no benefit to higher meal frequencies, providing further confidence in the validity of our findings.

A primary limitation of the analysis was that all studies to date were carried out in sedentary individuals. Thus, results cannot necessarily be generalized to those involved in regular exercise, particularly resistance training. There is compelling evidence that the muscles are sensitized to protein intake for at least 24 hours after a lifting session, suggesting a potential benefit to frequent feedings with protein rich foods in the post-exercise period. Whether this translates into greater long-term muscle growth remains to be determined.

It also isn’t clear if our findings are applicable to diets that include higher daily protein intakes. All of the studies analyzed used low to moderate protein doses, with the exception of the study by Arciero et al. Interestingly, this study did show significant improvements in body composition when an energy-equated high-protein diet (approximately 34% of total calories) was consumed in 6 versus 3 daily meals.

Take Home Points
The number of daily meals consumed does not appear to have much if any impact on changes in body fat, at least across a wide spectrum of feeding frequencies. Thus, the decision on how many meals to eat from this standpoint should come down to personal preference: if you find a benefit to having the structure of multiple meals throughout the day, then go for it; on the other hand, if you prefer to eat less frequently, that’s fine as well. The most important factor in this regard is achieving a negative energy balance, as well as ensuring that adequate dietary protein is consumed.

Although our analysis did not show differences between meal frequencies with respect to lean body mass changes, there is a logical basis for a hypertrophic benefit to consuming several protein-rich meals in those involved in regular resistance exercise. The anabolic effects of a meal last a maximum of 6 hours or so. Thus, consumption of at least 3 meals spaced out every 5 to 6 hours would seem to be optimal for keeping protein synthesis continually elevated and thus maximizing muscle protein accretion. This hypothesis needs further investigation in a controlled long-term study.


11 Comments

  1. Hey Brad,
    Most studies on this topic seem to be geared towards fat loss and not hypertrophy. I think we’re all on the same page when it comes to meal frequency being almost irrelevant when cutting but there just doesn’t seem to be much work done on meal frequency with regards to changes in body composition when in a calorie surplus for resistance trained individuals. I guess what we really need is a study where 2 groups with, say 1-3 years training experience and around the same weight/bf do the same routine and eat the same diet (say enough to gain 1lb weight per week with the same macro splits), except one group eats 6 meals, the other 3. Then we see if there is any difference in total lean mass gained.
    Is there anything like that or are you aware of any study that will look at that?
    Many thanks, and keep up the great work!

    Comment by Dolph — January 27, 2015 @ 6:32 am

  2. Agreed Dolph. To the best of my knowledge, such a study has not been conducted. It’s a topic that I hope to investigate at some point in the future.

    Brad

    Comment by Brad — January 31, 2015 @ 12:23 pm

  3. […] Are Frequent Meals Beneficial for Body Composition — Brad Schoenfeld […]

    Pingback by Top Fitness Articles of the Week - February 1, 2015 - Personal Trainer Development Center — January 31, 2015 @ 6:40 pm

  4. Dolph, these are the details of a study that was published at a conference back in 2008, showing greater gains in LBM with 3 vs 6 meals per day:
    https://www.duo.uio.no/bitstream/handle/10852/28684/Thexeffectxofxmealxfrequencyxonxbodyxcompositionxduringxxx..pdf?sequence=2

    Comment by Christian Finn — February 4, 2015 @ 8:27 am

  5. End of the link was cut off – here’s the short version: http://bit.ly/1LLDDq3

    Comment by Christian Finn — February 4, 2015 @ 8:32 am

  6. […] http://www.lookgreatnaked.com/blog/are-frequent-meals-beneficial-for-body-composition/ […]

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  7. […] Are Frequent Meals Beneficial for Body Composition via Brad […]

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  8. […] Una de las ideas que mas se manejan en el mundo del fitness es que el realizar un mayor número de comidas a lo largo del día es beneficioso para perder grasa. El especialista en hipertrofia Brad Schoenfeld nos presenta el siguiente análisis. […]

    Pingback by ADELGAZAR COMIENDO MÁS VECES: ¿ES BENEFICIOSO PARA LA COMPOSICIÓN CORPORAL? | Healthy PersonalTraining — February 8, 2015 @ 3:58 pm

  9. Thank you for this work and summary. No big surprises here, but nice to have all the relevant research wrapped up in a tight package. Completely anecdotal, but there is something to be said for the your milage may vary (YMMV) group. I’ve worked with many people over the years that find if they don’t eat frequent meals, they tend to suffer mood swings, and make poor choices at meal time. This could all be psychological, of course. I would like to conduct a study with active adults who believe their frequent eating habit is related to their fitness and well-being. I would restrict them to three meals a day, and see what the findings are. But just in case, I would like to be a safe distance when it comes to asking: “Mr Johnson, how is your mood today?” Just in case…

    Comment by Adam Trainor — February 19, 2015 @ 7:23 am

  10. What is the definition of a controlled log term study? And how many subject types would it take to run a full gamut of fitness levels?

    Comment by Ross — March 5, 2015 @ 8:25 pm

  11. […] Optimal meal frequency has been a hot topic for a long time. Some studies show that a high meal frequency is best, while others shows a low frequency is best. The latest meta-analysis by Aragon, Krieger and Schoenfeld, regarding meal frequency and body composition, shows that somewhere within 3-6meals is optimal (1). Yes, I am aware of that the meta-analysis showed a higher frequency might be better; however, this was mostly taken from one study. Therefore, it looks like it comes down to personal preferences and adherence, until more research is done. For a great review of the study, read Schoenfelds article here. […]

    Pingback by Regular or irregular meal frequency, does it matter? | FredFitology — April 25, 2015 @ 9:54 am

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