One of the new, progressively more accepted dietary ideas has to do with frequency of eating. It is believed that eating five or six smaller, versus three larger, meals per day is advantageous, especially in order to reduce weight. This new recommendation stands in direct contradiction with the following statement made by Ellen G. White:
Three meals a day and nothing between meals—not even an apple—should be the utmost limit of indulgence. Those who go further violate nature’s laws and will suffer the penalty.”1
Which of the two contradicting recommendations is more consistent with available research studies?
The idea that it is advantageous to eat more frequent smaller meals, instead of less frequent larger meals, each day is based on the assumption that more frequent eating increases the body's metabolic rate, which can lead to burning more calories. Even if we accept that this assumption is correct, there are good reasons to suspect that eating more frequently could actually increase the chances of gaining weight, in spite of the increased metabolic rate associated with more frequent eating. First, the majority of people in America, and many other countries, eat too much fat (thus providing many calories) and too few fiber-rich foods (fiber helps with feeling full). Furthermore, many do not have enough self-control to limit eating to smaller portions. Recommending eating smaller meals more frequently may give extra opportunities to overeat on the wrong (high fat/calories, fiber deprived) foods. Interestingly, societies where people live the longest and have the lowest prevalence of obesity and other chronic diseases, such as people living in the Valley of Vilcabamba, Ecuador, typically eat two to three meals a day, including a large breakfast and small dinner.
Findings from a research study published in the journal Obesity in 2012 yielded interesting results.2 Authors included 51 obese (average BMI = 35.5) individuals who were on average 51.0 years of age. These individuals were randomly assigned to either group 1 (n = 25), which was to ingest three meals per day or group 2 (n = 26), which was described as the grazing group, which was to eat at least 100 calories every 2-3 hours. Individuals from both groups ingested an identical number of calories (~1200 to 1500 per day, < 30% of calories from fat) and participated in a similar amount of physical activity (~200 minutes per week). In the next 6 months, participants assigned to group 1 consumed, on average, 3.2 meals per day, while those from group 2 had average meal frequency of 5.8 per day.
The graph below showed the average weight loss in 3 and 6 months for each of the two diet groups. Interestingly, a greater weight loss was observed among individuals from group 1, as indicative of greater body mass index (BMI) change. These individuals consumed fewer meals per day compared to those from group 2.
Furthermore, as it is shown on the next graph, individuals from group 1 lost more body fat compared to individuals from group 2.
The findings and the conclusion made by the author of this study are astonishing in light of the new dietary trend to eat more frequently in order to achieve a greater weight loss: “These results suggest that eating less frequently may be more helpful than eating more frequently for weight loss.”2
In 2013, the same journal (Obesity) published results of another study that assessed the impact of meal frequency on burning fat, hunger, fullness, and “desire to eat.”3 Authors included 15 non-obese individuals (BMI < 25). They were divided into two groups. The first group ingested 3 meals and the other group ingested 6 meals per day. Several times per day participants were asked the following questions: “How hungry are you right now?” “How full do you feel right now?” and “How much food could you eat right now?” Authors found no difference in the rate of fat burning (8.7 vs. 8.6 mJ/d). The graph below shows results regarding perceived hunger, fullness, and desire to eat for each of these two groups.
3M = three meals, 6M = six meals
The following two quotes from the manuscript describing this study’s findings speak volumes regarding the efficacy of the new diet trend to ingest more smaller meals vs. fewer larger meals:
These results suggest that there is no effect of meal frequency on EE [energy expenditure] or fat oxidation under isoenergetic states [both groups receiving the same amount of calories], which is in agreement with results from previous results. However, hunger…and the “desire to eat”…were significantly greater during 6 meals compared to 3 meals. With the more frequent meal pattern, subjects did not experience the same decreases in hunger or increases in fullness between meals….although consuming smaller, more frequent meals is often advocated as a means of controlling body weight, the present study suggests that this practice has no obvious advantages in terms of its effects on metabolism and appetite, and may, in fact, even have adverse effects on hunger and satiety.”3
In 2015, a manuscript describing findings from a meta-analysis that assessed the impact of meal frequency on weight loss was published in a journal Nutrition Reviews.4 Keep in mind, a meta-analysis is a type of summary of findings from more than one available studies. This particular meta-analysis was based on 15 studies. The following is the conclusion made by the authors of this meta-analysis:
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.”4
One does not have to be a scientist to understand that, consistent with the above conclusion, available research largely does not support the idea that consuming more frequent vs. less frequent meals is beneficial for weight loss.
The above-described findings regarding the impact of meal frequency on weight loss can be summarized by the following quote:
It is common practice for weight management clinicians to recommend increasing MF [meal frequency] as a strategy for weight management and to improve metabolic parameters. However, limited research exists investigating the effect of MF during controlled hypocaloric dietary interventions. Furthermore, MF literature often speculates with regard to efficacy of MF treatments based on research using normal weight, overweight/obese, or some combination, where much diversity exists within these various populations.”5
Clearly, according to the authors of the above quote, a recommendation to eat more frequent smaller instead of less frequent larger meals is based on a speculation, not on scientific findings.
Another important issue should be considered when discussing how many meals per day should be recommended for individuals to ingest. Although findings are not always consistent across studies, some studies have shown that increased meal frequency is associated with an increased risk of colorectal cancer. The same goes for irregular eating, which also has been associated with increased risk of bowel cancer. The term “irregular” refers not only to eating at different times of the day but also to frequent eating of small meals (or snacks). For example, a study conducted in Northern Italy showed that compared to those eating two meals a day, those who ate three meals a day had a 70 percent higher risk of developing colon cancer and had about a 40 percent higher risk of rectal cancer.6 People who consumed four meals had about 90 percent higher risk of cancer of the colon and rectum. Similar findings were reported in earlier studies. For example, authors of a study published in the journal Nutrition and Cancer found men with lowest meal frequency having half the risk of colon cancer compared to men with higher meal frequency.7 Higher risk of colon and rectum cancers seem to be the result of bile, a substance made in the liver and secreted into the intestine to aid in fat digestion.
It seems prudent to conclude that eating more frequent smaller meals instead of less frequent larger meals per day has little support in available scientific studies. It is likely that this new dietary recommendation is nothing but recent hype that, just as has been the case with many other diet trends, will soon go away. It will be prudent for Adventists to stick to Mrs. White’s advice that, “At least five or six hours should intervene between the meals; and most persons who give the plan a trial, will find that two meals a day are better than three.”1
Notes & References:
- Ellen G. White. Councils on Diets and Foods.
- Bachman JL, Raynor HA. Effects of manipulating eating frequency during a behavioral weight loss intervention: a pilot randomized controlled trial. Obesity (Silver Spring),2012;20(5):985-992.
- Ohkawara K, Cornier MA, Kohrt WM, Melanson EL. Effects of increased meal frequency on fat oxidation and perceived hunger. Obesity (Silver Spring),2013;21(2):336-343.
- Schoenfeld BJ, Aragon AA, Krieger JW. Effects of meal frequency on weight loss and body composition: a meta-analysis. Nutrition Reviews,2015;73(2):69-82.
- Kulovitz MG, Kravitz LR, Mermier C, Gibson AL, Conn CA, Kolkmeyer D, Kerksick CM. Potential role of meal frequency as a strategy for weight loss and health in overweight or obese adults. Nutrition.2014;30(4):386-392.
- Franceschi S, La Vecchia C, Bidoli E, Negri E, Talamini R. Meal frequency and risk of colorectal cancer. Cancer Research, 1992;52:3589-3592.
- Wei JT, Connelly AE, Satia JA, Martin CF, Sandler RS. Eating frequency and colon cancer risk. Nutr Cancer. 2004;50(1):16-22.
Roman Pawlak, Ph.D, RD is Associate Professor of Nutrition in the Department of Nutrition Science at East Carolina University.
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This is a companion discussion topic for the original entry at http://spectrummagazine.org/node/8677