Meal frequency can potentially matter, a little, but it depends purely on your goals. I’ve previously written blog posts about the myths that surround the importance of breakfast, and eating carbs at night. These both touch on the misconception that meal timing is important. So feel free to click on the links and have a read. But for now we will focus on meal frequency.
One of the most common phrases you have probably heard is…
‘Eating little and often will boost your metabolism,
and keep you energized throughout the day’
Unfortunately, or fortunately, depending where your biases lie, this is another of those often-quoted myths. Most studies that find an association between meal frequency and various health markers are observational studies, these generally show correlation not causation. The biggest problem is that they only show a small snap shot of behavior and are often flawed and biased. This leads to a lot of scientific nonsense being published. Sounds all clever and smart but when you logically and critically look at it, you can find all the faults, misconceptions, and generally pick the papers apart.
Here’s an example to understand the flawed nature of observational studies…
‘People who often watch TV on average have a higher BMI
than people who don’t watch TV very often.
Therefore we can conclude that TV causes obesity.’
Ridiculous right. Correlation not causation. TV doesn’t cause obesity; there will be something else going on. Maybe the people not watching TV that often are more active in general. Maybe, just maybe, they are more health conscious.
Anyway back to meal frequency and whether it has any impact on metabolism.
From more reliable studies we know that there is no significant evidence that meal frequency impacts metabolism or the total amount of fat lost.
In one paper I looked at the researchers found that when doubly labeled water was used to assess total 24-hour energy expenditure there was no difference between nibbling and gorging. You probably won’t know this but doubly labeled water is the gold standard method of measuring energy expenditure. So when you see this method used in a study it’s certainly something to take notice of, much more so than an observational study in my opinion.
I also found a 6-month study looking at meal frequency when eating at a maintenance level. This is great as a lot of studies tend to look at the effects of a calorie restricted diet on health markers, where as this study in particular focused on a reduced meal frequency (1 meal per day) compared to a standard 3 meals per day, with the calories matched as closely as possible. The researchers were looking for health indicators in healthy, normal-weight adults.
So what did the results show?
Well, the one meal per day group actually lost a little bodyweight and body fat compared to the 3 meals per day group. If you look at this critically though you could put this down to a slight difference in daily calories. Although 65 kcals a day isn’t overly significant, it could account for this drop over a 6-month period. This study also found meal frequency had no effect on heart rate, body temperature, and most blood variables that were measured.
However, the 1 meal per day group did report an increase in feelings of hunger, but that’s not surprising at all. You would expect it. Interestingly, they did find a significant decrease in cortisol levels. Again though, critically thinking, you could put this down to the timing of the blood collection. Cortisol is typically elevated in the morning and decreases later in the afternoon. This is when the blood collection of the 1 meal per day group was taken. Although, the blood collected from both groups was taken after fasting. So is it really that significant?
What this study really shows is that when meal frequency is decreased there is very little difference found in the majority of health markers. So you really don’t have that much to worry about if you are focusing on weight-loss or health.
But what if your goal is all about the gains, and increasing muscle mass?
Don’t worry there is evidence in the benefit of increasing meal frequency for muscle gains. Maybe that’s another blog post in the making?
What I will say is that if your goals are weight-loss, muscle retention or even just to be healthier, then the intake of frequent, small meals is nothing more than a myth. Countless studies show there is no real benefit to eating more often. It does nothing to your metabolism. If anything eating fewer meals may actually be healthier.
Now I’m not saying ignore meal frequency or meal timing for that matter, before anyone makes any ridiculous comments, but for most of us, focus on the basics of nutrition first. Energy balance. Get that right and then see where you are. It’s really all about personal preference.
When you are hungry. Eat. Before you feel full. Stop eating. When you are thirsty. Drink.