A: Anna, it sounds like you’re ready to make serious changes. Whether it’s doctor’s orders, an upcoming high school reunion, a New Year’s resolution, a significant other (or, potential significant other), or that pair of skinny jeans staring at you in the closet, you have the motivation you need to get started on your weight-loss journey. You’ve signed up for a personal trainer. You’ve got all of your BioTrust supplements. You’re ready to take on the dreaded d-word: The Diet.
So it’s only natural you’re starting to ask one of the first questions we hear from many people starting on this journey. “When it comes to body composition and fat loss, does meal frequency matter?”
You might find this surprising with all of the strongly held opinions around this subject—including your trainer’s—but the conditional answer is no. Meal frequency probably doesn’t matter.
It’s conditional because it does hinge on the much more important factors of food choices and portion control. That is, when calories and macronutrients are controlled, meal frequency doesn’t matter. Better said, if you eat the right types of food (i.e., food choices) in the right amounts (i.e., portion control), meal frequency becomes a matter of personal preference.
Thus, if you do a better job of eating more metabolism-boosting protein and health-promoting vegetables over the course of six meals a day, then that may be the best strategy for you. However, if you do better with a few larger meals, then go for it.
Are There Downsides to Six Meals a Day?
Yes, there are downsides to each approach. Starting with smaller, more frequent feedings, it just doesn’t bode well for many people for some of the following reasons:
Downside to six meals a day:
- It typically requires significant meal planning and preparation.
- Many people “watch the clock” either waiting for the next meal or making sure they don’t miss one.
- You spend a lot of time eating.
- Many folks tend to schedule their days around their meals.
- This population tends to be more apt to get HANGRY.
Downside to three meals a day:
- Some folks have a much harder time with portion control.
- Likewise, some people will find it more challenging to include as much nutrient-dense food in a shorter period of time and/or fewer feedings.
Is there any research that actually compares meal frequency? Yes, as a matter of fact, there is quite a bit of research on the topic. Researchers from Purdue performed a meal frequency experiment where they divided overweight men into multiple groups. One group consumed six meals a day, evenly spread out every two hours. Another group consumed precisely the same total number of calories in three feedings, which were separated by five hours. Both groups were following a calorie-restricted diet, but the scientists noted no significant differences in weight loss as a result of meal frequency.
Interestingly, the authors of the study did find that those subjects who ate fewer, larger meals experienced greater late-night fullness, which could potentially reduce the chances of snacking. Furthermore, the researchers noted that there were more compliance issues with the group assigned to eating six meals per day. On top of the meal frequency portion of the study, the scientists found that, compared to a normal-protein diet (i.e., 14% of calories), a high-protein diet (i.e., 25% of calories) collectively led to improved appetite and satiety and lower late-night urges to eat as well as reduced preoccupation with food.
In another study that appeared in the British Journal of Nutrition, scientists again separated subjects into high meal frequency (i.e., 6 meals per day) and low meal frequency (i.e., 3 meals per day) groups. Both groups of subjects followed a reduced-calorie diet, and at the end of eight weeks, the researchers found no significant difference in body weight, fat mass, lean body mass, or body mass index. The authors concluded that increased meal frequency “does not promote greater body weight loss.”
Super Belly Fat Burning Combo:
In a study funded by the National Institute on Aging and the US Department of Agriculture, researchers questioned the notion that, despite its commonality, “three squares” (i.e., three meals a day) is optimal for health. The scientists separated subjects into two groups. One group consumed three meals per day while the other group consumed only one.
The groups both consumed an equal number of calories daily, which were assigned at maintenance level (i.e., not a calorie-restricted study). After eight weeks, the researchers found that reduced meal frequency (i.e., one meal per day), without a reduction in calories, led to a significant modification in body composition including reductions in body fat, as well as a significant decrease in cortisol.
Perhaps most important, the renowned International Society of Sports Nutrition, one of the world’s top authorities on sports nutrition, recently released their position stand on meal frequency. It should be noted that, when an organization of this magnitude issues a position statement on any given topic, it’s typically regarded as solid evidence—the closest to the truth as we know from science.
In said statement, the organization concluded that increasing meal frequency does not appear to favorably change body composition.
Can You Stoke Your Metabolism?
What about the idea of “stoking” the metabolism with smaller, more frequent meals (like six meals a day)?
There are several components that make up one’s metabolic rate (i.e., energy expenditure). The argument on consuming smaller, more frequent meals to stoke metabolism rests on the notion that eating more frequently will increase what’s known as the Thermic Effect of Feeding (TEF), which refers to the amount of energy the body uses to digest, absorb, and assimilate all of the nutrients we consume (from food).
Sure, it makes sense. If you eat 6 meals a day, there will be more increases (i.e., pulses) in metabolic rate due to the TEF associated with each meal. However, do more pulses mean a greater overall response? Nope. As a matter of fact, the most extensive review of studies performed on TEF and various meal frequencies, ranging between 1 and 17 meals, concluded:
“Studies using whole-body calorimetry and doubly-labelled water to assess total 24 h energy expenditure find no difference between nibbling and gorging.” [NOTE: This is NOT an excuse to gorge oneself. Rather, it is to make a point regarding TEF. This is a completely other issue in and of itself.]
Furthermore, the researchers also negated the notion that meal frequency has an effect on weight loss and concluded that “any effects of meal pattern on the regulation of body weight are likely to be mediated through effects on the food intake side of the energy balance equation.” Hmmm… that sounds a lot like food choices and portion control.
You may have heard that if you miss a meal, the body will go into starvation mode. But is that true?
Not so much. Efficient adaptation to famine was no doubt a significant metabolic consequence during evolution. A decrease in metabolic rate during times of starvation was actually a good thing, as it increased the likelihood of living until one perhaps found some sustenance.
However, it’s important to delineate starvation from missing a meal or even fasting for 24 hours. The idea that skipping a meal or implementing a short fast or intermittent fasting (IF) results in a reduced metabolic rate is not substantiated by science.
As a matter of fact, the earliest that scientific research has noted a decrease in metabolic rate in response to fasting is after 60 hours, which resulted in an 8% drop. Other research has shown that a dip in metabolic rate does not occur until 72 to 90 hours of fasting. Even with more pronounced IF protocols that implement daily fasts, the longest time without food is typically about 36 hours, which may actually have the opposite-than-expected effect on metabolic rate.
Ironically, there is frequently a short-term boost in metabolism with fasting. Studies have shown an increase of 4 to 10% in metabolic rate with fasting up to 36 – 48 hours. This likely is the result of increased catecholamines (i.e., epinephrine and norepinephrine), which serve to provide more energy and sharpen focus. This can be seen as desirable as the body is now in somewhat of a “fight” mode to find food.
At some point—as mentioned above—this would be counterproductive, and the body would have to decrease metabolic rate in order to simply survive.
With all that being said, the best approach, in terms of meal frequency, may be the one that best works for you. That is, as long as you choose the right types of foods and eat them in the appropriate amounts, then meal frequency doesn’t matter.
I hope this helps, Anna!