Recently, a question came up from a reader on another website (go here to read the full post) about the validity that you should eat 3-6 meals daily. This individual referred to an article written in The New York Times touting that there is really no benefit to eating frequently. Instead of responding, knowing full well that some people just have their minds made up, I decided to post on my blog giving information to back up the reasoning behind frequent meals.
1. To be clear, I stated in my post that a minimum of 3 meals should be eating each day. The studies mentioned by The NY Times compared 3 meals to 6 meals. I do not believe that eating only 3 meals is detrimental; however, less than 3 meals is damaging. Not only for the reasons of increased fat storage and depletion of glycogen, but also because people overeat when they are deprived for long periods during the day. I have seen this in practice over and over again. I have had hundreds of patients who go all day without eating, and then tell me that they are so ravenous by the end of the day that they eat everything they can find. I have had some patients find that they are consuming several thousand calories in the evening. So yes, while the end result is calories in versus calories out, a) you are more likely to metabolize more calories per day with more frequent meals; and b) people who eat less than three times per day, typically eat more calories than they need in a day in one or two sittings.
2. Magazines, Newspapers, and other media present the research how they would like to present it. There is always a way to take portions of a study out of context and bend it to appear how you would like it. The people who write these articles are not always qualified to interpret research and advise others on it. Sometimes, the articles are written simply for “interesting reading”. To decide whether or not to take heed, check their credentials.
2. I did take a look at The NY Times article and the research that it was referring to. Notice that the author also mentioned a scientific study that did, in fact, show a metabolic advantage to eating small frequent meals. ( Jenkins, Wolever, Vuksan, Brighenti, Cunnane, Rao, Jenkins, Bucklye, Patten, Singer, et al. Nibbling versus gorging: metabolic advantages of increased meal frequency. N Engl J Med. 1989 Oct 5;321(14):929-34.) Part of the story is that, in science, many studies will be conflicting, so it takes a lot of analysis and MANY scientific studies before conclusions can really be drawn. To be honest, after looking at all three of the studies mentioned in the article, I don’t believe any of them were well designed. They all include an extremely small amount of subjects and they all look at different outcomes. Unfortunately, I was also unable to pull up the entire studies; however, looking at the abstract is much more telling than a line or two in The NY Times. However, I have a few more comments on the two studies that “disproved” the need for small frequent meals. One of the studies gave every subject the same amount of calories. Everyone surely does not have the same caloric needs; therefore, you will have some people consuming more than necessary and others consuming less. How can you conclude anything from that? The other study was only conducted for two weeks and it did, in fact, show a decrease in fat oxidation. Overall, it looks like better studies need to be completed.
3. Regardless of the fact that the above-mentioned studies were really not conducted well, classic studies do show that resting energy expenditure is, in fact, decreased during prolonged periods of not eating. In the first 24 hours of starvation, glycogen stores are depleted, so there is no “fat melting away”. Glycogen is stored with water, so when glycogen is used up, water loss occurs. This leads to…….weight loss! But not fat loss! Fat loss occurs in the later stages of starvation. In the early stages of starvation, fat is preserved. (Barton. Nutrition support in critical illness. Nutr Clin Pract 9: 127. 1994) Another study shows that resting metabolic rate does drop by as much as 15% within 2 weeks of inadequate food intake. (Ravussin, Swinburn. Effect of caloric restriction and weight loss on energy expenditure. In: Wadden TA, Van Ittalie TB (eds.) Treatment of the Seriously Obese Patient. New York: Guilford Press, 1992.)
4. When you are not eating often, you can think of insulin release like hills and valleys. This is unfortunate because it causes large fluctuations in blood sugar, which is not healthy for organs. Also, when insulin is peaking due to a large influx of food after fasting, fat storage is promoted.
Hopefully this post helped to clear up any possible confusion!