Debunking the Meal Frequency Myth

How often have you been told to consume five or six small meals a day? Chances are you’ve heard your fair share. For years, health authorities have stated that a higher meal frequency is significant in maintaining an optimum metabolism and that by consuming fewer meals, you would bring about your body’s starvation mechanism, causing you to store body fat. With such staunch claims as this by health magazines, personal trainers, and the media alike, how can they be refuted? Here’s a word for you– science. Recent studies have revealed that the former is not true.

Why, then, is this advice considered the mainstream? Perhaps it was another marketing ploy by big magazine publishers back in the day to draw in subscribers. Or may it was the best way to help people understand the need for eating less. Nobody wanted to discredit the claims; it made sense. After all, wouldn’t eating smaller meals at a higher frequency seem to place lesser stress on the metabolism? It would certainly seem that way.

Here’s the justification behind all this:

Twenty-two females between the ages of 18 and 74 (M=30, SD=15) volunteered for the study. All of the females had to meet specific criteria to be a participant. The criteria were based on variables that could have affected metabolism. Participants were not to have exercised in the previous three months. They were not to have any known metabolic disorders. They were not to be taking any medications or dietary supplements that could potentially affect metabolism. Lastly, participants were not to be pregnant or lactating.
Procedure

Participants were accepted on a rolling basis. When an individual committed to participate in the study, she scheduled a time for an orientation session. At the orientation session, each participant signed an informed consent form. She was then given specific instructions on the desired method to record what and how much she ate in the diet diary. At this time, the participant was also debriefed on how the procedure for obtaining resting metabolic rate would be conducted. At the end of seven days the diet diary was turned into the research team. In addition, a preprandial RMR test was conducted in the University of Wisconsin-La Crosse Human Performance Lab. Prior to testing, participants were to minimize their physical exertion and to have fasted for at least six hours. The Quinton QMC metabolic cart was calibrated and then the mouthpiece was attached to the participant. She was then instructed to lie in the supine position on a padded table. Resting metabolic rate was measured by indirect calorimetry. The test was performed for 20 minutes; however, only data from the last five minutes was utilized in the study. Diet diaries were analyzed using NutraQuesttm nutritional software (Mc Graw Hill Inc.).

RESULTS
Average meal frequency (AMF) was calculated by averaging each participant’s total meals a day. This number was then averaged across participants to yield an overall AMF of 2.7 meals a day. Participants who reported an average daily meal frequency (ADMF) of greater than 2.7 were categorized into the high meal frequency (HMF) group. Participants who reported an ADMF of less than 2.7 were categorized into the low meal frequency (LMF) group. An eating session was defined as anytime during the day a participant consumed any amount of food. For each participant, an average daily eating session (ADES) was calculated by adding up the total eating sessions in the seven day period and dividing by seven. The overall ADES was calculated by averaging all of the participants’ ADES, which yielded 4.7 daily eating sessions. Those participants who reported an average greater than 4.7 eating sessions were categorized in the high eating sessions group (HES). Those participants who reported an average lower than 4.7 eating sessions were categorized in the low eating sessions group (LES). Analysis of Covariance (ANCOVA) was used to detect a relationship between HMF or LMF and RMR and also between HES or LES and RMR. Average daily caloric intake and age were used as covariants to determine any effects on RMR. Alpha level was set at .05.
Results of ANCOVA revealed no significant relationship between HMF and RMR and also between LMF and RMR (F=0.001, p=0.981). Also the results of the ANCOVA revealed no significant relationship between LES and RMR as well as HES and RMR (F=0.601, p=0.450).

-Goodman-Larson et al. UW-L Journal of Undergraduate Research VI (2003).

Now, if reading all that scientific nomenclature is not your fancy, here’s the conclusion that was made following the study: Regardless of meal frequency by each individual, there was no correlation between frequency and metabolism. Tell that to your personal trainer!

From a psychological standpoint, eating less per meal at a higher meal frequency makes sense in that it may prevent one from overeating and those late night gorges, especially when on a reduced calorie diet. Although not significant, the appetite suppressive qualities of a higher frequency meal intake may help during dieting.

Many will argue that by eating less frequently with larger meals, you will raise blood insulin levels, causing lipogenesis (the storing of fat). This model’s theory was that the raised insulin levels increased LPL activity (Lipoprotein Lipase was the supposed rate limiter for free fatty acid uptake and fat metabolism/synthesis), thus it was the single factor for fat storage. The problem with the insulin > fat storage model is outdated and there are many other factors outside of insulin which dictate fat storage and metabolism. For instance, Chlyomicrons alone (byproducts of fat digested in the stomach) can rouse free fatty acid uptake and triglyceride production, even in the absence of insulin. Bye-bye insulin model!

It all comes down to your macronutrient breakdown and your total caloric intake. It’s entirely a matter of preference as to whether or not you choose to have half a dozen meals or three meals. More active folks might get hungrier more often, so six meals sounds like a treat. I eat more than six meals because I eat like a horse and I’m always on the go. I know many extremely ripped and lean individuals that eat three or four meals in a day. Eat however often you feel you need to eat, within reason. If you are hungry, chances are your body is telling you to eat something, so shut it up by feeding it. If you are wise with your caloric intake, you may find that you can eat a few decently portioned meals and snack and graze intermittently to keep hunger satiated. Then again, if eating all day isn’t your fancy, go with three meals (I’d keep the baseline at three, since it’s hard to down four digit calorie meals (>1000 kcal) at one sitting without bloating up like the Pillsbury Doughboy).