What’s Better, 3 or 6 Meals Per Day?
Here’s what you need to know…
- Research doesn’t support the idea that eating more frequently “stokes the metabolic furnace.”
- There’s evidence that eating multiple small meals can increase protein synthesis, but this has only been shown in cases where protein intake is very low.
- It’s best to experiment with different meal frequencies and see what works best for you. Above all, choose a frequency of feeding that fits your lifestyle.
You’ve heard the claims that eating small, frequent meals is the key to
getting jacked. It speeds up the metabolism, satisfies hunger, and promotes
better glucose control – a body comp homerun. At least that’s what gym lore
would have you believe.
Does the evidence support the practice of spreading out meals over the
course of a day? Let’s look at the research.
Metabolism
Proponents of eating frequent meals claim that it helps to “stoke the
metabolic furnace.” This is based on the set point theory, which dictates
that your body strives to maintain enough energy (i.e., body fat) to survive
the next famine. So when you go without eating for more than a few hours,
the body senses deprivation and shifts into “starvation mode,” and part of
the starvation response is to decrease resting energy expenditure. In
effect, the body slows down its metabolic rate to conserve energy.
While such claims may sound logical on the surface, there’s scant evidence
to support that it actually occurs. LeBlanc et al. found that feeding dogs
four small meals doubled the thermogenic response compared to eating the
same number of total calories as a large single meal. A follow-up study by
the same researchers found that humans also experienced heightened
thermogenesis with more frequent feedings.
On the other hand, many other studies have failed to show that meal
frequency has a tangible effect on energy expenditure. The body of evidence
simply doesn’t support any increases in metabolism as a result of
partitioning nutrient intake over multiple meals.
Basic logic would argue against any enhanced effect of eating frequently on
dietary thermogenesis. Thermogenic enhancements from frequent meals are
commonly attributed to the thermic effect of food (TEF).
Simply, the TEF is the energy expended as heat resulting from the digestion
of food sources. The various macronutrients have differing thermic effects,
with protein causing the greatest energy expenditure and fat the least. The
TEF of a typical mixed meal is estimated to be around 10% of calories
consumed.
With this as background, let’s take a look at how spreading out meals would
affect the TEF in a 2400 calorie-a-day diet. If you ate three 800-calorie
meals, the TEF would be 80 calories per meal. Multiply this by the number of
daily meals (three) and you’ll arrive at a total TEF of 240 calories.
Now if you were to consume that same 2400-calorie diet over six meals, the
TEF would be 40 calories per meal. Do the math and you’ll wind up with the
same additional 240 calories burned as in the three-meal-a-day diet.
Assuming macronutrient content and total calories remain constant, there is no difference in thermogenesis! The tables below illustrate this concept.
Table 1: 2400 Calories as Three Daily Meals
| Meal | kCal | TEF |
|---|---|---|
| 1 | 800 | 80 |
| 2 | 800 | 80 |
| 3 | 800 | 80 |
Table 2: 2400 Calories as Six Daily Meals
| Meal | kCal | TEF | Meal | kCal | TEF |
|---|---|---|---|---|---|
| 1 | 400 | 40 | 4 | 400 | 40 |
| 2 | 400 | 40 | 5 | 400 | 40 |
| 3 | 400 | 40 | 6 | 400 | 40 |
Appetite and Hunger
Proponents of frequent meals often claim that it helps to control appetite
and hunger. It’s well documented that weight management is primarily a
function of energy balance – take in more calories than you expend and
you’ll gain weight; create a caloric deficit and you’ll lose weight.
It’s postulated that there’s a tendency towards hypoglycemia (low blood
sugar) during the lengthy post-prandial periods associated with infrequent
meals. In an attempt to restore blood sugar, your body signals the
hypothalamus that it needs food, especially simple carbohydrates. Hunger
pangs ensue and you invariably end up eating more than you otherwise would,
often as refined sweets. This sets up the vicious cycle of overeating and
uncontrolled insulin secretions – a surefire route to unwanted weight
gain.
However, research doesn’t appear to support these lofty claims either.
While a few studies have reported that subjects weren’t as hungry when meals
were spaced out over the course of a day, others have failed to detect
differences on indices of appetite and hunger regardless of feeding
frequency.
In fact, some studies have found that eating three as opposed to six daily
meals actually promotes greater feelings of satiety. What’s more, evidence is conflicting for
how the number of meals consumed affects hunger-related hormones. Taken as a
whole, the belief that it’s more satisfying to spread out nutrient intake is
at best equivocal and likely related to individual factors.
Insulin Levels
Another claim often cited to support spreading meals throughout the day is
that it has an “insulin-friendly” effect. According to the hypothesis,
eating a few large meals causes a surge in blood sugar, which in turn leads
to a spike in insulin levels. Given its role as a storage hormone, the
bigger insulin peaks switch on mechanisms that increase fat deposition.
Sounds ominous, but the validity of such claims are at best shaky.
A number of studies have shown that consuming more frequent meals produces
a favorable effect on glucose homeostasis. This invariably translates into
reduced insulin spikes and lower mean insulin concentrations. But the
overriding question here is, do these findings matter? From a fat loss
standpoint, the answer appears to be not really.
Munsters et al. found that while frequent meals produced significantly
lower peaks and more even glucose and insulin values compared with fewer
feedings, there was no difference in fat oxidation between groups. Simply,
both eating patterns resulted in the same amount of fat burned.
This study was noteworthy for its tightly controlled methodology. The
researchers employed a crossover design where the same subjects consumed
both diets and the exact same types and amounts of food. What’s more, the
subjects were lean, healthy adults, thereby more relevant to those who
regularly work out.
The bottom line is that those who focus on the insulinemic effects on fat
loss/accumulation in a healthy population have their eye on the wrong prize
– the enemy is excess calories, not insulin.
Body Composition
Evaluating the acute effects of frequent meals can provide interesting
clues as to potential ramifications of such an approach. However, the only
thing that ultimately matters is whether eating more frequently improves
body composition. This is where things get kind of tricky.
The study most often cited by frequent meal proponents involved competitive
boxers who were placed on a 1200-calorie diet for two weeks. One group
consumed the calories as two daily meals while the other group spaced out
eating over six times a day.
At study’s end, the frequent feeding group retained a greater amount of
lean body mass compared to the two-meal-a-day group with similar total
weight loss between groups. While these findings are intriguing, it must be
noted that the study period was very short. Whether such results would
continue over the long-term is speculative.
What’s more, total protein intake amounted to just 60 grams a day – an
amount far below what any hard-training athlete would require to prevent
muscle catabolism. These limitations make it difficult to draw any firm
conclusions on the topic.
A recent study by Arciero et al.Seems to further support a greater daily
meal frequency. Briefly, the study employed an intricate design where two of
the groups consumed a high-protein diet amounting to 35% of total calories
of either three or six meals-a-day for approximately two months. Both groups
showed approximately the same amount of fat loss (2.5 kilograms for the
three meals versus 2.7 kilograms for the six meals). No biggie here.
However, the group who consumed frequent meals actually gained lean body
mass (0.6 kilograms), versus a loss of LBM in the group that ate three daily
meals (-0.9 kilograms). That equates to about 3 pounds of LBM – certainly
nothing to sneeze at.
Again, results need to be taken with a grain of salt. In this case,
subjects were overweight women who didn’t participate in any regimented
exercise, never mind an intense resistance training program. Whether similar
results would be seen in serious lifters is anyone’s guess.
What’s more, it seems curious that frequency would have such a stark impact
on lean mass increases given that the anabolic effects of protein
consumption have been shown to last for up to six hours. This raises doubts
as to the validity of the body composition measurements in this study.
In opposition to the aforementioned findings, a number of other studies
have shown no body composition benefits to consuming more frequent meals. In
fact, a well-controlled randomized crossover trial by Stote et al. found
that a group of normal-weight middle-aged adults lost more body fat
following a one-meal-a-day regimen compared to eating the same number of
calories spaced out over three daily meals.
