by Todd C. Killebrew, N.D.
Ask almost any doctor, dietician, personal trainer or other expert about dieting and they will likely respond that one of the best ways to lose weight is to “graze” throughout the day. This usually refers to eating four to six, or even more, small meals per day rather than the traditional three meals per day. It is one of those recommendations that has been repeated so often by so many people and for so long that it has become ingrained in almost all of us. The problem is, it isn’t true and it doesn’t work.
How or where this misbelief originated I’m not sure, but there is little to no scientific research to back it up. In fact, virtually every study done on this topic has shown either no difference between eating several small meals daily vs fewer large meals or they have shown that eating fewer, larger meals actually helps with weight loss.
- A small study presented at the Society for Endocrinology BES 2014 compared both approaches to eating and found that it does not matter which one is taken as long as total calorie intake was reduced. The women in the study alternated between eating five meals one day and two meals the next day, and it was found that they burned the same amount of calories on both days.
- A meta-analysis from the July 2009 Nutrition Review examined 176 studies regarding meal frequency and its impact on weight and health. A portion of these studies focused specifically on weight loss interventions. The evidence from the studies suggested that there was no association between frequency of eating and weight gain/loss or other health outcomes.
- The results of a small study of type II diabetics presented at a June 2013 American Diabetes Association conference showed that over a 12 week period, participants who ate only a large breakfast and lunch lost an average of 1.23 points from their BMI. Comparatively, participants who ate the same number of total calories spread over six smaller meals throughout the day lost only 0.82 points. Additionally, those who ate only twice a day experienced improved insulin sensitivity, which leads to better blood sugar control.
Let’s take a look at some other reasons why eating several small meals per day is not more beneficial than the traditional three large meals. And let’s examine how eating two to three large meals may actually be healthier. Let’s start by looking at a few false assumptions.
A common misconception is that by depriving your body of food for more than a few hours at a time (i,e. fasting), your body’s metabolism will slow down to conserve energy to compensate for the lack of caloric intake, resulting in increased fat storage when you eat your next meal. However, when you look at the biochemistry of how metabolism works this simply isn’t true. In fact, as meals are spaced farther apart the body becomes more adept at tapping into fat reserves for energy rather than relying upon energy directly from meals.
- One study actually found an increase in metabolic rate (i.e., the body starts burning more calories) after 36 hours of fasting and this increase lasted up to 72 hours. Even more surprising was a study that looked at “alternate day fasting” (fasting every other day). In this study the participants were instructed to eat twice as much food on the days when they could eat. The results showed no decrease in metabolic rate, rather it remained stable from day to day (American Journal of Clinical Nutrition 2005).
- Two more studies where participants consumed the same caloric intake came to the same conclusion: Eating small meals frequently vs larger meals less frequently had no impact on metabolism. (The European Journal of Clinical Nutrition in 1991 and The British Journal of Nutrition in 2008)
Some would argue that eating more frequently helps to keep hunger in check. Unfortunately there are few studies looking at this particular aspect but there is one study that stands out:
- In the September 2010, Obesity (Silver Spring) found that eating three larger high-protein meals led to greater fullness and appetite control than eating six smaller high protein meals (i.e., those who ate more frequently were hungrier more often). Other studies have found similar, though less consistent, results with high fat consumption.
But what about blood sugar control? Doesn’t eating frequently help keep blood sugar stabilized? In short, NO! This is perhaps an even more surprising finding and one that cuts against the grain of common medical advice for diabetics.
- A study from the July 2010 Department of Exercise Science at Syracuse University examined two groups of people: One group ate 6 high carbohydrate meals per day and the other ate 3 high carb meals per day (the number of total calories consumed was the same). Those who ate 3 high carb meals per day initially experienced greater spikes in blood sugar after the meals but their blood sugar came back down and remained lower on average throughout the day than did the blood sugar levels of the 6 high carb meal group. In other words, eating frequently can lead to more “stable” blood sugar levels, but those levels are too high. Eating more less frequently results in lower average blood sugar levels.
Another interesting point is that the body does a remarkable job of maintaining its blood sugar levels over a long period of time without food. In fact, during long periods without food our bodies have an amazing ability to shift to what is called ketogenesis, which is when ketone bodies rather than glucose are utilized for energy. More simply put, the body is burning fat rather than carbohydrates for energy, which is what we want for weight loss. Through this process we can effectively run for as long as we have fat stores available. The reality is our body does not need frequent meals to regulate its blood sugar levels. To be clear, this is not to encourage long-term fasting, which can have serious health consequences such as muscle and organ wasting. And of course those who have hypoglycemia need to take extra steps to keep their blood sugar levels from dropping too low.
On a side note, many who believe they have hypoglycemia do not actually have clinically low blood sugar levels after meals even though they manifest symptoms such as altered mood, shakiness, weakness, fatigue, etc. These symptoms can be alleviated by avoiding simple carbohydrates and basing your diet on protein, fiber, fats and complex carbohydrates.
The bottom line is that while eating frequent meals doesn’t necessarily lead to weight gain in of itself – given that caloric intake remains consistent – it does result in higher average blood sugar levels and decreased satiety, which can lead to overeating and weight gain. In contrast, we have seen that eating fewer, larger meals helps maintain lower average blood sugar levels, increases satiety and metabolism, and may even help with weight loss. As it turns out, the traditional three meals per day is not such a bad way to eat after all.
In order of appearance, photos courtesy kimubert, Thogru, cyclonebill, Janine, Forest & Kim Starr, storebukkebruse, Janine, William Cho, Tim Lucas, Bill Branson, BruceBlaus via Creative Commons Licensing