Perhaps the most popular meal frequency often recommended is to eat 6 meals a day. People recommend 6 meals per day cause they believe that the digestive system will have to keep working, which supposedly will keep the metabolism high and burn more calories throughout the day. Moreover, if you went too long between meals, you put yourself at risk of a slowed metabolism!
Looking at all of this make some sense to it. But, So, let’s dig deep into the 6 meals a day myth.
When we look pass face value, the truth begins to unravel. In the research of eating more meals to increase your metabolism, it’s metabolic nonsense.
As far back as 1997, we already had epidemiological reviews which found weak evidence linking greater weight loss or energy expenditure to eating more frequent smaller meals. The overall conclusion was that total food intake was the only thing that really mattered.
In the recent researches, we see that not much has changed.
A review of 25 studies released in 2009 once again concluded that there was no association between eating frequency and weight loss.
In terms of metabolism, a 2012 study compared 3 meals to 14 meals a day and still found no differences in resting metabolic rates within a 24-hour analysis.
Same goes for one study 3 years prior, which noted 3 meals and 3 snacks a day was just as effective as only 3 meals a day for weight loss when the total food amount is equal.
As far as digestion, measurements of thermic effect of food, the amount of energy it takes for your body to digest your food, showed that changes in meal frequencies, again, did not alter thermic rates. The only thing that mattered is the size of the meal, with larger meals requiring more energy to break the extra food.
But the proverbial coup de grace came in a 2015 meta-analysis. In their analysis, they initially found that higher feeding frequencies did associate with greater reductions in fat and body fat percentage as well as an increase in fat-free lean mass. But, the researchers realized that all of these positive findings stem from one single study out of the 15 analyzed. This study, which looked at boxers eating 2 or 6 meals per day, might have run into the issue of accurately reporting physical activity.
When this study was removed from the review, statistical values point towards meal frequency having, again, virtually no effect on fat mass, lean mass, or weight loss. So, it seems like it’s settled. Alone, eating 6 meals or more a day won’t provide extra benefits.
Also, when it comes to the claims of fewer meals slowing metabolism, we might be able to learn a bit from the research on fasting. On such research, one study in 1994 found that fasting for 12 hours had no effect on metabolism. Same in 2005, where eating every other day did nothing to metabolism after 3 weeks. Interestingly enough, the 1994 study saw that after 36 hours of fasting, metabolism increased. Not exactly standard practice for most, but it’s interesting to see that research actually suggest the opposite of the initial claim.
Now, the big question: How many meals should you eat a day?
As always, your main goal should be eating a healthy diet, tracking your intake, and proper exercise. Whether you choose to meet this goal with 2, 3, or 6 meals per day is ultimately up to whichever you can stick to the most.
Some research does show that more meals can help with hunger and satiety, but on the same note, some studies show it does not effect it at all.
All that being said, the claims about six meals per day and metabolism is mostly more fad talk. As with other fads, just ignore it. It will not be long until another fad rolls along.