Meal frequency examined

Effects of meal frequency on weight loss and body composition: a meta-analysis

Authors: Brad Jon Schoenfeld, Alan Albert Aragon, James W. Krieger

Abstract

It has been hypothesized that eating small, frequent meals enhances fat loss and helps to achieve better weight maintenance. Several observational studies lend support to this hypothesis, with an inverse relationship noted between the frequency of eating and adiposity. The purpose of this narrative review is to present and discuss a meta-analysis with regression that evaluated experimental research on meal frequency with respect to changes in fat mass and lean mass. A total of 15 studies were identified that investigated meal frequency in accordance with the criteria outlined. Feeding frequency was positively associated with reductions in fat mass and body fat percentage as well as an increase in fat-free mass. However, sensitivity analysis of the data showed that the positive findings were the product of a single study, casting doubt as to whether more frequent meals confer beneficial effects on body composition. In conclusion, although the initial results of this meta-analysis suggest a potential benefit of increased feeding frequencies for enhancing body composition, these findings need to be interpreted with circumspection.

TL:DR

  • increased meal frequency does not provide you with a metabolic advantage
  • have 3-4 meals with 20-40g of protein at each meal
  • protein requirements increases with age as anabolic sensitivity decreases
  • ultimately adherence to diet matters the most. choose a meal frequency that suits your preferences and lifestye

Quotes from the article

Increasing meal frequency is often promoted as a beneficial strategy for reducing fat mass.3 Justification for this claim generally revolves around the belief that frequent feedings enhance postprandial thermogenesis, defined as the increase in heat production that occurs for up to 8 h after consumption of a meal.

However, the majority of studies on the topic have failed to show a positive relationship between meal frequency and energy expenditure,46–50 and 1 trial with adult women actually found a greater thermic effect from consuming a single food bolus as compared with 6 small calorie-equated meals.45 Interestingly, Smeets et al.10 found no differences in diet-induced thermogenesis or energy expenditure in the consumption of 2 versus 3 calorie-equated meals a day but did note that 24-h fat oxidation was greater in the 3-meal condition.
In combination, the totality of findings indicate that the significant impact of meal frequency on measures of fat loss is a false positive rather than a true effect and can be attributed to undue weighting of a single study
The consumption of frequent meals also has been postulated to enhance the retention of FFM and possibly even increase muscle protein accretion. The anabolic impact of feeding has been estimated to last approximately 5–6 h based on the postprandial rate of amino acid metabolism.51 Some studies in rodents52,53 and in humans54,55 suggest that the rise in muscle protein synthesis (MPS) following consumption of amino acids or a protein-rich meal is more transient, with levels returning to baseline after approximately 3 h. This phenomenon is thought to occur despite sustained elevations in amino acid availability, leading to the “muscle-full hypothesis” whereby MPS becomes refractory and circulating amino acids are oxidized rather than used for tissue-building purposes when a bolus of more than approximately 20 g of amino acids is consumed by young individuals. Anabolic sensitivity is diminished with age so that the saturable limit in the elderly rises to approximately 40 g per serving. The muscle-full hypothesis, therefore, suggests that multiple daily feedings of 20–40 g, depending on age, are needed to maximize anabolism.

The initial analysis performed for this review, with number of meals as a continuous predictor, did, in fact, show a trend for positive effects of increased feeding frequencies on FFM, and this became significant in the full and reduced models. However, as with the effects on fat mass, sensitivity analysis revealed that the results were unduly influenced by the results of Iwao et al.28 and removal of this study negated any benefit related to the number of meals consumed per day, with a change in P value from 0.03 to 0.96. This suggests that findings can be attributed to a false positive and that varying the frequency of feeding does not lead to a greater accumulation of FFM. The reasons for these divergent findings remain elusive. However, it should be noted that acute measures of MPS do not necessarily correlate with long-term increases in muscle hypertrophy.

 

Conclusion

Although the initial results of the present meta-analysis suggest a potential benefit of increased feeding frequencies for enhancing body composition, these findings need to be interpreted with circumspection. The positive relationship between the number of meals consumed and improvements in body composition were largely attributed to the results of a single study, calling into question the veracity of results. Moreover, the small difference in magnitude of effect between frequencies suggests that any potential benefits, if they exist at all, have limited practical significance.

Given that adherence is of primary concern with respect to nutritional prescription, the number of daily meals consumed should come down to personal choice if one’s goal is to improve body composition.There is emerging evidence that an irregular eating pattern can have negative metabolic effects, at least in the absence of formal exercise.71,72 This gives credence to the hypothesis that it may be beneficial to stay consistent with a given meal frequency throughout the week.

Emphasis mine.

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