Are you a "nibbler" or a "gorger"? Online reports are popping up, again, regarding a new study that challenges the notion that frequent, small meals is better than less, larger meals per day for weight loss. For example, Women's Health reposted a recent Time.com article, which states, "don't believe the hype, dieters. Eating five meals a day won't make you any skinnier, a new study shows."
Actually, this new study is nothing new, but there is a catch, that most people completely miss with this myth.
Traditionally, most people think that eating several, smaller meals per day will boost your metabolism, and to a degree it is true. During and right after eating we get a slight boost in metabolism, called the 'thermic effect of food' (TEF). In other words, TEF is the energy expenditure (measured in calories) that we expend while digesting, absorbing, and distributing nutrients of a meal. The TEF makes up about 10% of our total daily caloric expenditure, so the thought is, "eat more often, expend more calories".
In the early 1960's, Dr. Gwinup and colleagues noticed that many animals ingest small portions of food through a day (i.e. nibblers), while man tends to eat large meals, infrequenlty (i.e. gorgers). In addition, research up to that point had suggested that if a rat, a nibbler, is trained to eat his diet in one or two meals per day – obesity, high blood sugar, and high cholesterol develop.
What Does the Research Say?
So, in 1963, Dr. Gwinup and colleagues published the "Effect of nibbling versus gorging on serum lipids in man", and their findings suggested transitioning from 3 meals a day to nibbling, serum lipids decreased, but when frequency changed from 3 meals a day to gorging, there was a prompt increase in serum lipid levels.
Since this time, many studies have looked at the frequency of meal intake.
Here are some highlights:
- 1971 – Finkelstein and Fryer found no differences in weight loss, after 60 days, between 4 overweight female university students who ate six meals a day, and 4 female students who ate 3 isocaloric meals (same amount of calories).
- 1989 – Jenkins and colleagues compared 7 normal weight men for 2 weeks, who either ate 17 snacks per day (the nibbling diet) or 3 meals a day. As compared to the 3 meals per day, the 'nibbling diet' reduced resting total cholesterol, LPL, and serum insulin.
- 1997 – Bellisle, McDevitt, and Prentice conducted a review of all previous studies on meal frequency, and concluded, ". . . with the exception of a single study, there is no evidence that weight loss on hypoenergetic (low calorie) regimens is altered by meal frequency." In other words, if eating a low calorie diet, meal frequency did not matter.
- 2014 – And, the study of recent interest, Piya and colleagues compared 2 versus 5 isocaloric, high fat (50%) meals per day, over 2 days, in 24 lean and obese women. There was no difference in 24 hour energy expenditure, thus no "boost" in metabolism. They also found that eating these high fat meals, so frequently, might produce an increased inflammatory and metabolic disease risk.
Is There a Catch? YES
So, why is this potentially not a slam dunk, closed case?
- 1997 – Klem and colleagues found in a landmark study that, on average, 784 women and men who successfully lost and maintained at least 30 pounds for 5 years, had average of 5 eating episodes per day! In addition, on average, the eating episodes ranged from around 2 to 8 eating episodes per day. Thus, they all succeeded with different meal frequencies.
- 1997 – The same Bellisle, McDevitt, and Prentice review, discussed earlier, concluded that the effects of meal pattern on our body weight is most likely a result of urging us into eating too much (weight gain) or a healthy amount (weight loss).
- 1998 – McGuire and colleagues found that weight-loss maintainers used more dietary behavioral strategies, such as substituting low fat for high fat foods, than did weight regainers.
- 2005 – Forslund and colleagues compared 4529 obese, middle-aged persons with 1092 normal weight persons, and found that obese subjects were more frequent snackers of unhealthy, fatty foods, which resulted in postive energy intake (eating too many calories).
- 2014 – And even the Piya and colleagues study concluded that self-monitoring food intake was what mattered most for weight loss. Not sure why all the online articles leave this out!?
So, the take-home message is that meal frequency can lead to both weight loss or or weight gain. We must use what works for us. If eating 7-8 times a day allows you to eat healthfully, then eat 7-8 times per day. If you eat more healthfully using 3 meals a day, then eat 3 meals a day.
The keys are to:
- Pay attention, on purpose, to what you eat = self-monitor
- Eat with self-control
- Choose healthy options, thus controlling the quantity with the quality of the food.
** Remember, you would have to eat 21.5 cups of baby spinach to equal 1 Twinkie cake! Calories are the same (approximately 150 Calories), but are drastically different in their nutritional value.