I remember the first time a nutritionist came and spoke to a class I took in undergrad. He was talking about meal frequency and how “6-8 small meals boost your metabolism.” He then gave us an example, he said if you are going to eat a pizza it would be better if you split it up and had pieces throughout the day as opposed to eating it in one sitting. From everything you have seen in the media or been told by some bro’s at the gym, this probably makes sense to you and sounds familiar. At the time I didn’t know better, I heard what he said and figured I’d give it a try. After all, he was a “qualified nutritionist.” It wasn’t until I really became interested in nutrition and started doing my own research that I found how wrong he really was.
When you look at the studies on meal frequency things start to become clear. The information provided in a lot of studies can be misleading. For example, we have always been lead to believe that breakfast is the most important meal of the day, but why? I assure you that it isn’t, especially if you want to lose weight. So a study concludes that people who skip breakfast are usually overweight and binge later in the day. Ok, so what? Is it the skipping breakfast that made them fat? Or do they have poor eating habits? I mean if you skip breakfast and then stuff your face with fast food from lunch on then sure you will probably be overweight. I’m sure you know plenty of people who have a large breakfast and are overweight; would you conclude that breakfast causes them to be fat? Probably not, so you see the flawed reasoning being used.
In studies where they examine the 3 square meals a day it’s important to look at the representative/control group used. Usually these are typical Americans, and as you know America has an obesity problem. So it’s likely that they already have poor eating habits which can skew how we view the results of 3 meals. A person with poor eating habits will get fat by eating 3 or 6 meals. From my own experience and experience of my clients, fat gain is more the result of suboptimal food choices and NOT meal frequency. Diets like The Warrior Diet or Leangains prove that you can get extremely fit and lean by eating 3 and even in some cases, 1 meal a day. Let’s look at Japan for example. Their traditional diet is 3 meals a day but their food choices come from fish, eggs, vegetables, rice, etc. They happen to have some of the lowest obesity and diabetes rates in the world.
In a study by Bellisle, et al. the researchers set out to compare the thermic effect of food (TEF) on frequent vs. less frequent meals. What they found is that the thermic effect of food was marginally higher with more frequent meals but they concluded that the results were not unanimous OR overly significant. They determined that energy balance, calories in vs. calories out, was more important than the number of meals. The TEF isn’t the only important thing to consider. Diet experts have been telling people for years that they should attempt to keep blood sugar levels steady and stable. Basically this leads to people eating carbohydrates more frequently. But this is not sound advice. By constantly feeding yourself carbohydrates you will keep insulin levels elevated thus leading to a reduction in insulin sensitivity. Why do we want insulin sensitivity? Well because insulin is a very powerful anabolic hormone that can either be your best friend or worst nightmare. The better your insulin sensitivity the more efficient you will be at handling your carbs. You will have “better” nutrient repartitioning. In simple terms, insulin will direct where the glucose in the blood stream will go. If you are always eating carbs you are in danger of becoming insulin resistant. With insulin resistance your body will secrete more insulin than necessary, since your body/cells have become resistant to its effects, excess glucose will undergo denovo lipogenesis and be stored in adipose tissue (fat). There is much more to say regarding insulin sensitivity and resistance but that’s for another post.
Ok, back on meal frequency. In another study, “Effect of meal frequency on glucose and insulin excursions over the course of a day”, the researchers found that normal-weight participants who ate 6 meals a day had much higher blood sugar levels than those who ate 3 (Holmstrup, 2010). Calories and total carbs were kept the same. Therefore, it appears that insulin was more effective in lowering blood sugar in those eating fewer meals. Less frequent meals or carbohydrate feedings leads to lower overall blood glucose levels, which is helpful when trying to recomp your body. It’s also important as it can protect you from developing such things like diabetes or metabolic syndrome.
In this debate about how many meals to eat it’s important to remember that both can work. If you have a consistent plan with reasonable levels of macronutrients, have good food choices, exercise, and stay within your calorie goals; you will be fine. But for those of you who are used to eating carbs at every single meal of the day, try limiting the number of meals you have them with; not necessarily how many total carbs. See how your body responds. Remember, diet is always going to be specific to the individual. What works for one person may not work for you so don’t get caught up in the “one size fits all” approach to dieting.
Bellisle et al. 1997. “Meal frequency and energy balance.” Br J Nutr Apr;77 Suppl 1:S57-70.
Holmstrup et al. 2010. “Effect of meal frequency on glucose and insulin excursions over the course of a day.”