Guest blog by Kelechi Opara
Much like Jason in the Friday the 13th movie franchise, the myth of high frequency feeding refuses to die.
Some still believe and books still tout that there is a METABOLIC ADVANTAGE when you increase the frequency of your meals by spreading them through out the day.
An example would be spreading your meals from 3 to 6 in a belief that it will increase a your metabolic rate—> better fat oxidation being the end result.
Following along the same lines of this belief —> eating less frequently (2-3 times a day) will cause your metabolism to slow down or missing a meal will cause your body to go in a catabolic state–break down of muscle tissue for fuel.
To be honest, years ago I used to believe the same thing. Fortunately, I am a strong believer of the aphorism “the mind is like a parachute, it works best when its open” so I overcame this limiting belief years ago when I found overwhelming evidence through research and application.
The Thermic Effect Of Feeding (TEF)
This myth originated from the misunderstanding of TEF: thermic effect of feeding (one of SEVERAL factors influencing metabolic rate)…the amount of calories burned by the body when processing the food you eat. The thermic effect of feeding averages to about 10% (meal composition also influences TEF) . This means a person consuming 300 calories can expect to burn 30 calories during digestion so every time we eat our metabolic rate spikes slightly during that particular time.
The reasoning became “if I spread my meals out through the day, I will cause TEF more often raising my metabolic rate and burn more fat”. However, the truth is this: At the same total amount of calories and meal composition, the person consuming 3 meals per day is going to burn the same amount of calories through TEF as the person consuming 6 meals a day.
The metabolism of the person consuming 6 meals a day isn’t going to be faster than the person consuming 3 meals a day. The calories burned through TEF at the end of the day will be the same for both. You see even though the person consuming 6 meals have 6 spikes in their metabolic rate via TEF…the spikes are smaller. The person consuming 3 larger meals will have 3 LARGER spikes resulting in the same amount of calories burned at the end of the day.
To expound further: Two people consuming 3000 calories total: one person divides the 3000 calories into 6 SMALLER meals result:–> smaller calories burned (during the 6 instances of smaller feedings which caused smaller TEFs) will result in the same number of calories burned at the end of the day for the other person who divides the 3000 calories into 3 LARGER meals result:–>Larger calories burned ( during the 3 instances of larger feedings which caused Larger TEFs ). Numerous studies such as the one below have demonstrated no metabolic advantage of eating more frequently…
Br J Nutr. 1997 Apr;77 Suppl 1:S57-70.
Meal frequency and energy balance.
Bellisle F, McDevitt R, Prentice AM.
INSERM U341, Hotel Dieu de Paris, France.
Several epidemiological studies have observed an inverse relationship between people’s habitual frequency of eating and body weight, leading to the suggestion that a ‘nibbling’ meal pattern may help in the avoidance of obesity. A review of all pertinent studies shows that, although many fail to find any significant relationship, the relationship is consistently inverse in those that do observe a relationship.
However, this finding is highly vulnerable to the probable confounding effects of post hoc changes in dietary patterns as a consequence of weight gain and to dietary under-reporting which undoubtedly invalidates some of the studies. We conclude that the epidemiological evidence is at best very weak, and almost certainly represents an artefact. A detailed review of the possible mechanistic explanations for a metabolic advantage of nibbling meal patterns failed to reveal significant benefits in respect of energy expenditure.
Although some short-term studies suggest that the thermic effect of feeding is higher when an isoenergetic test load is divided into multiple small meals, other studies refute this, and most are neutral. More importantly, studies using whole-body calorimetry and doubly-labelled water to assess total 24 h energy expenditure find no difference between nibbling and gorging.
Finally, with the exception of a single study, there is no evidence that weight loss on hypoenergetic regimens is altered by meal frequency. We conclude that any effects of meal pattern on the regulation of body weight are likely to be mediated through effects on the food intake side of the energy balance equation.
This is just one of many studies that discredits the “high frequent feeding = faster metabolic rate”. Add to it is the fact that you have people who practice intermittent fasting or what some call “warrior diet” ( Eating one big meal a day or 3 meals in a 1 to 8 hour period while fasting for 12 to 23 hours) with no effect on their metabolism and no loss of muscle mass. Our metabolism isn’t easily changed, for example it takes around 3-4 days of strict dieting for our metabolism to even slow down. Which brings me to the other myth about meal frequency…
Myth: Missing meals will cause muscle loss.
It takes about 5-6 hours for a typical meal to be completely out of your system–determined by macro nutrient composition. For example, amino acids are still being released in your blood stream 7 hours later after ingestion of 43 grams of casein protein. This means when people eat every 2 or 3 hours the previous meal still haven’t finished digesting.
Never mind the fact that it will take 24 hours after last meal (if you were to go without eating) for liver glycogen to completely to deplete . The liver is the switch that tells the body whether to go in a catabolic state. This would indicate that you have about 24 hours (some sources say 18) before your body starts using your muscle for fuel. Thus missing a meal or eating less frequently isn’t going to cause muscle loss.
The key is having the adequate amount calories for your activity level by the end of the day. Along the same lines there are actually studies that show eating too frequently (every 2 hours for instance) isn’t conducive protein synthesis–> gaining mass. In other words if both people were eating the same amount of calories, the person eating every 4 hours would gain more muscle mass than the person eating every 2 hours .
What about appetite control?
In the same vein albeit a little off the subject of meal frequency and metabolism. Some people often mention the fact that high frequency meals controls appetite thus ensuring compliance for people dieting to lose weight. However, studies (and experience) show that this isn’t the case…the study below shows meal frequency isn’t the determining factor for controlling appetite:
Br J Nutr. 2010 Apr;103(8):1098-101. Epub 2009 Nov 30.
Increased meal frequency does not promote greater weight loss in subjects who were prescribed an 8-week equi-energetic energy-restricted diet.
Cameron JD, Cyr MJ, Doucet E.
Behavioural and Metabolic Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada.
There have been reports of an inverse relationship between meal frequency (MF) and adiposity. It has been postulated that this may be explained by favourable effects of increased MF on appetite control and possibly on gut peptides as well. The main goal of the present study was to investigate whether using a high MF could lead to a greater weight loss than that obtained with a low MF under conditions of similar energy restriction.
Subjects were randomised into two treatment arms (high MF = 3 meals+3 snacks/d or low MF = 3 meals/d) and subjected to the same dietary energy restriction of – 2931 kJ/d for 8 weeks. Sixteen obese adults (n 8 women and 8 men; age 34.6 (sd 9.5); BMI 37.1 (sd 4.5) kg/m2) completed the study. Overall, there was a 4.7 % decrease in body weight (P < 0.01); similarly, significant decreases were noted in fat mass ( – 3.1 (sd 2.9) kg; P < 0.01), lean body mass ( – 2.0 (sd 3.1) kg; P < 0.05) and BMI ( – 1.7 (sd 0.8) kg/m2; P < 0.01).
However, there were NS differences between the low- and high-MF groups for adiposity indices, appetite measurements or gut peptides (peptide YY and ghrelin) either before or after the intervention. We conclude that increasing MF does not promote greater body weight loss under the conditions described in the present study.
As you can see from the conclusions the hormones peptide YY (a satiety hormone) and ghrelin (hunger hormone) were the same in both groups. This shows that the high meal frequency group didn’t fair any better in terms of appetite control (or weight loss for that matter) any more than the low frequency meal group.
Meal frequency should be determined on an individual needs–> not based on the idea that it will speed up the metabolism, suppress appetite or even increase muscle mass (via continuous ingestion of protein every 2 hours). It would be ludicrous to divide the caloric requirement of a person whose daily caloric requirement is 1200 calories into 6 meals.
At the same time, it wouldn’t be a good idea to divide up the caloric requirement of an individual whose daily caloric requirement is 6000 calories into 3 meals. Instead base meal frequency on what’s convenient for you, the frequency that’s going to allow you to reach your nutritional goal.