Yes, lower meal frequency displayed more optimal attributes, but it's difficult to say what will happen long term... However, we can see that with lower meal frequency, weight loss variables such as [hunger, satiety, metabolic rate, insulin and glucose control] were all favorably adjusted...
Meal Frequency: The Argument Rages On...
Meal frequency or how often you consume food has been a topic of discussion for years.
Many people take meal frequency to actually be a driving force behind how your metabolism functions and further, how easily you lose weight.
It’s postulated that by having fewer meals, and thus larger ones, you create this metabolic environment that is unsuitable for markers of health. It’s thought that because of the large amount of food, this leads to higher insulin secretion, poorer control over blood glucose and potentially higher levels of hunger in between.
Additionally, many people at least somewhat literate with exercise science believe that a higher frequency of eating will “stoke the metabolic fire” even though this theory has been pretty much debunked.
It’s because of many of these thoughts that the scientists in the present study tested subjects for 36 hours multiple times in a metabolic ward and evaluated insulin, blood glucose responses, relative appetite and also how the body utilized nutrients when meal frequency is higher and of course, lower.
12 male participants, under the age of 40 were recruited for this study. The authors mentioned that this was an all male study to avoid potential differences of energy expenditure at the hands of menstrual cycle fluctuations.
After initial screening, all preliminary tests were taken (glucose testing, insulin testing, etc.). Further, this study took place inside of a metabolic ward, essentially a chamber that monitors gas exchange (what fuels your body is burning).
Upon beginning, subjects were placed into 1 of 2 groups. Group one consumed total calories within 3 meals while group two consumed total calories across a total of 14 meals. Measurements indicated that total energy intake did not differ between groups, meaning that frequency of meal intake rather than total calorie intake is what’s being evaluated here.
This study was a 2-way crossover design that included a washout period of at least 1 week. This means that both groups completed both trials but waited at least 1 week in between. This is fairly standard for a crossover design and this allows researchers to observe reactions to both protocols to avoid potential outliers or mishaps.
Each time each participant entered the metabolic chamber, testing proceeded for 36 hours. During that time, all energy intake, expenditure and other testing (insulin, glucose, nutrient partitioning, etc) was completed.
Summary Of Procedures
12 males participated in a crossover design, testing the effect of low frequency (3 meals) versus high frequency (14 meals) of the same calorie amount on measurements like insulin control, glucose control, appetite and how the body actually uses nutrients when consumed. This was completed in a metabolic ward, increasing the confidence we have in the measurements reported.
Energy Expenditure & Nutrient Partitioning
As you can see, energy intake between groups was not different. However, we see two distinct areas in which the differing meal frequencies did have some effect.
Interestingly, we actually see a significant difference in Rest Metabolic Rate (RMR) between groups. And more interesting is that the low frequency meal group actually displayed a higher RMR than the high frequency group, which goes in the face of most people’s idea of higher frequency meal consumption.
Second, it’s important to point out the increase in protein oxidation with lower frequency. At first glance, this may be reason for alarm, but really, it’s just because the amount of protein per meal is higher.
When a large bolus of protein is consumed, the amount of protein that gets oxidized just increases for a number of different reasons. But that makes sense. The body is constantly oxidizing proteins and synthesizing new ones. It makes sense that as protein intake increases, so to would the body’s responses of oxidation and synthesis (2).
Overall, there were no major differences between the two groups apart from potential benefit in terms of RMR for the low frequency group. The change in protein oxidation is likely explained by the larger amount of protein per meal and lis likely not cause for concern.
Metabolic Markers (Glucose, Insulin & Free Fatty Acids)
When measuring blood glucose and insulin responses, we see a fairly typical response here. For the low frequency group, we see distinct time points in which insulin is elevated, which reflects when food was consumed. In the higher frequency group however, we don’t really see any large spikes, which makes sense because the insulin response would be relative to the amount of glucose ingested and the type of carbohydrate consumed (more + fast glucose = larger insulin response).
In terms of free fatty acid availability, it’s difficult to know if this is relevant, especially because total fat oxidation wasn’t different between groups. It’s important to at least point out that even though the low frequency diet had a tendency for higher amounts of free fatty acids, that didn’t actually result in more fat being oxidized. Thus, even though it might free the fat from cells, you still need to metabolize them for energy to actually see any meaningful body composition change. Keep in mind that long term that might be relevant.
Hunger & Satiety
In what might actually be the most important variable, we can see that when larger meals were consumed, we see a drastic dip in hunger and a drastic uptick in satiety, compared to higher frequency, which really had almost no effect.
This is highly relevant and important since hunger is one of the biggest reasons diets fail. By consuming larger meals, digestion slows and you stay fuller for longer, allowing for better control over appetite.
The effect that larger meals with lower frequencies has on appetite and feelings of fullness cannot be discounted here.
This Was Very Short Term
Keep in mind that the time points that individuals were studied was a very short amount of time, evaluating specific responses to food and food frequencies.
Thus, the findings here are not indicative of what will happen long term. However, it’s likely that the effect of lower frequency, larger size meals on appetite and satiety may actually be relevant long term.
Keep in mind, in other articles, I’ve discussed how ghrelin cells that secrete the hunger hormone ghrelin, operate on a circadian rhythm of when you normally eat, secreting just before meals.
Theoretically, if you’re on a higher frequency diet schedule and these cells adapt, you may be having secretions of ghrelin making your hungry, very often throughout the day, which might make dieting much more difficult. Keep in mind this is theoretical but certainly plausible.
14 Meals May Be A Bit High
Make sure to notice that 14 meals is a bit high and not recommended. There’s simply no reason to consume this amount of meals. Not to mention, unless you’re consuming 4 thousand calories a day, the amount of protein you're consuming per meal may be inadequate for actually stimulating muscle growth. Studies indicate there is a certainly threshold that needs to be hit and if you’re only consuming 10-15 grams per meal, you may not be hitting it (3).
A better approach would be to have a maximum of 5-6 meals per day, all containing 30+ grams of high quality protein. In that case, we might see a difference.
Individual Responses Don’t Always Paint The full Picture
It’s important to remember that even though many of these measurements may play a role in weight changes, no single one is indicative of what will happen.
Surely, we see more optimal responses with lower frequency compared to higher frequency. Better insulin and glucose control, better control over appetite and satiety, etc. Together, those variables make a decent diet.
But remember with studies like this, we don’t see a huge effect on either side. Yes, lower frequency displayed more optimal attributes but it’s difficult to say what will happen long term. Surely many people have found success with higher frequency diets so it’s still possible.
However, we can see that with lower frequencies, most variables that are relevant to weight loss (hunger, metabolic rate, insulin and glucose control) were favorably changed with lower frequencies. Thus, it at least reveals that initially, lower frequencies may be appropriate.
How To Use This Information
Overall, it seems that having a lower frequency of meal intake might be optimal. Keep in mind though that’s relevant to your food intake.
If for example, you’re consuming 200 grams of protein per day, you may need to increase the number of meals you eat. Just keep most of them similar in terms of energy and protein amount per meal.
Additionally, other research indicates that having regularly dispersed dosages of adequate amounts of protein is best for building and maintaining muscle. Thus, consider dispersing your meals to ensure that you’re consuming in the range of 30-60 grams of protein per meal (4).
Overall, it seems fairly obvious that there isn’t a huge benefit of higher frequency meals and doing so may actually be ill advised. However, we don’t know how this would change if the higher frequency of meal intakes was more like 5-6, rather than 14.
While 3 even meals may be appropriate, 14 small meals certainly are not.
Why This Should Matter To You
Many people accidentally assume that higher frequency meals would potentially be more advantageous for weight loss, but a mounting body of evidence, including the present, indicates that’s probably not the answer. Further, if you’re hoping to favorably adjust your body composition, this information gives you additional guidance to do so.