To date, there is no strong evidence that suggests that an increase or decrease in meal frequency leads to an increase in metabolic rate and body fat loss. When calories are similar, meal frequencies can vary between three to six meals a day; there appears to be no significant difference in metabolic rate or overall fat loss.
DOES INTERMITTENT FASTING SLOW METABOLISM SUMMARY
- Intermittent fasting does not slow metabolism.
- Mini meals provide consumed more frequently have no metabolic advantage to eating less frequently when calories are controlled over the day.
- It is recommended that a minimum of 3-4 high-quality meals be consumed evenly throughout the day to optimize protein synthesis.
- Studies measuring body composition (DEXA scan), bioelectrical impedance, and other body composition analysis tools have found no meaningful effect on increasing meal frequency and lean muscle/fat loss when calories are equated.
SLOW VS FAST METABOLISM
How often have you heard someone say they are gaining weight because they have a slow metabolism? People ask how to reset metabolism for weight loss. Is there a reset metabolism button in the body somewhere??
A popular diet is the Fast Metabolism Diet, a 28 days plan that cycles through rotating periods of high-protein, high-carb, and high-fat eating each week to rev up your metabolism. There has never been a study to show that rotating macros will enhance metabolism! The best fat loss is by adhering to a long-term calorie-restricted diet in which you slowly decrease calories. Fast weight loss is associated with greater losses in lean muscle mass.
DOES METABOLISM AFTER 40 SLOW DOWN?
Many people believe after 40; your metabolic rate plunges to zero. Many believe that their metabolism is damaged. Older adults will commonly ask fitness professionals how to fix a damaged metabolism after 40. Older adults tend to become more sedentary, which can contribute to weight gain.
Your metabolism does slow down with age, but the good news is that it does not start happening until age 60! How to increase metabolism after 40/ how to boost metabolism after 40 is a frequent search query on google.
People look for metabolism booster drinks, metabolism-boosting exercises (i.e., metabolic training/metabolic workout), foods that boost metabolism, cooking spices to boost metabolism, how to fix a damaged metabolism after dieting, etc. There is a lot of money to be made with products or special exercises that boost metabolism; however, many need to provide meaningful metabolic boosts.
Mini Meals are Better for Your Metabolism
Eating 6 small meals a day has been advocated to enhance metabolism during strength training and weight management in the fitness industry. Many have suggested that intermittent fasting will slow your metabolism down because of the prolonged feeding time hours. The advantages of small mini-meals over the day, as opposed to three large meals, are:
- Better appetite control.
- More stable blood glucose over the day.
- Increased thermic effect of food (TEF).
- Enhanced fat metabolism.
You will find millions of articles on “foods that boost metabolism for a flat stomach.” Please don’t bother wasting your time reading these articles.
DOES EATING THREE MEALS A DAY AND INTERMITTENT FASTING SLOW METABOLISM?
Many have suggested that less frequent meals and intermittent fasting slow metabolic rate. First, most studies have found little meaningful effect on basal metabolic rate with increased meal thermogenesis with frequent meals. (1-4) Basal metabolism definition is the number of calories you burn to sustain life-sustaining functions if you stay in bed all day. This is commonly referred to as basal metabolic rate.
Many utilize the basal metabolic rate formula to calculate the body’s metabolism rate. Second, the effect of appetite control is debatable, some research has shown decreased appetite in response to more frequent meals, and others have found increased appetite. Third, frequent small meals do not seem to have any favorable effects on fat metabolism.
DOES A FAST METABOLISM DIET MEAL PLAN CONSIST OF SIX MEALS A DAY?
Researchers had subjects follow a calorie-controlled diet and divided them into three or six meals daily. Both groups had similar effects on fat metabolism and 24-hour energy expenditure. (5) There was no difference in fat metabolism or calories burned when calories were similar. Another study compared isocaloric diets and had subjects eat three times a day (i.e., 8 am, 12 pm, 7 pm) or a high-frequency meal 14 times throughout the day (small mini-meals every 2 hours).
There was no difference in fat oxidation or burning between the groups. Interestingly, the three-meals-a-day group had a greater increase in protein breakdown, suggesting that increased meal frequency may result in better muscle preservation. (6)
In another study, comparing 2 versus six meals a day with a similar calorie diet resulted in similar changes in body weight and fat mass. However, the two meals-per-day group lost more lean mass than the six meals per day.(7)
Other Studies
In 2013, a study found broke subjects into three groups: high protein six meals per day (35% protein), high protein three meals a day (35% protein), or low protein three meals a day (15% protein). Calories were matched, and the rest of the macros were divided among carbs and fats. Interestingly, they were told to maintain their current calories, not restrict them.
The groups that received the high protein diet lost more body fat than the low protein group. All the subjects were then put in a caloric deficit (25% reduction in kcal intake [3500 kcal deficit each week]) for both the high protein groups (three and six times a day) lost more body fat than the low protein group.
Only the high protein group, six times a day, gained lean mass. The researchers suggested frequent high-protein meals resulted in a metabolic advantage during dieting.(8) The differences between the three and six-meal groups were very small. The key to these studies is the research showing that high protein is the key; whether you eat three or six meals a day is a preference.
There was a minimal effect on body composition in a meta-analysis of meal frequency on weight loss and body composition.(9) In a 2019 review of the literature of 2124 individuals, there was no relationship between meal frequency and body fat, lean mass, or waist circumference.(10)
ISSN Recommendations on Meal Frequency
The International Society for Sports Nutrition Position paper on meal frequency(11), which is accessible online for free (https://jissn.biomedcentral.com/articles/10.1186/1550-2783-8-4) regarding meal frequency and body composition are:
1.) Increasing meal frequency does not appear to favorably change body composition in sedentary populations.
2.) If protein levels are adequate, increasing meal frequency during periods of caloric restriction may preserve lean body mass in athletic populations. Increasing the amount of protein combined with various sources of protein is best for maximizing protein synthesis.
3.) Increased meal frequency appears to have a positive effect on various blood markers of health, particularly LDL cholesterol, total cholesterol, and insulin.
4.) Increased meal frequency does not appear to significantly enhance diet-induced thermogenesis, total energy expenditure, or resting metabolic rate.
5.) Increasing meal frequency appears to help decrease hunger and improve appetite control.
To date, there is no strong evidence that suggests that an increase or decrease in meal frequency leads to an increase in metabolic rate and body fat loss. When calories are similar, meal frequencies can vary between three to six meals a day; there appears to be no significant difference in metabolic rate or overall fat loss. Meal frequency should be a choice rather than telling a person it’s mandatory to eat six meals a day. It should be a diet that best fits their individual needs.
Tips for Intermittent Fasting
Ensure your protein is hitting the appropriate ranges, whether trying to gain or lose weight. It has been found that meal frequency has little impact as long as total protein intake is met. For example, a study found that rugby who consumed 2.6-2.7 g/kg of protein per day (1.18-1.19 grams per pound of body weight), meal frequency (four vs. six meals) resulted in similar increases in lean mass. (12)
Similar findings have been found in elite rowers. Fewer meals (i.e., three meals per day) resulted in similar body composition gains as more frequent meals (i.e., six meals per day) when calories and macronutrients were equal.(13)
Intermittent Fasting vs Multiple Meals Per Day
A meal frequency of four times a day should be effective for maximizing protein synthesis. The classic study that I base four meals per day is the study in which whey protein ingestion (4 times per day × 20 grams every 3 hours) post-workout was found to be more effective for protein synthesis than the ingestion of larger protein dosages less frequently (2 times per day× 40 g every 6 h) or smaller, suboptimum dosages of protein (8 times per day × 10 g every 1.5 hours).(14)
20 grams of high-quality protein per meal is the muscle full effect, in which no further intakes of protein will stimulate muscle protein synthesis.(15)
Protein After Exercise
After exercise, the protein needs should be increased to 40 grams. This is based on earlier research showing that 40 grams of protein maximally stimulate muscle protein synthesis after exercise.(16, 17) Also, it was found that each meal contains .4g/kg of protein per meal (i.e., 20 grams).(18) If you consumed four meals a day, this would hit the 1.6g/kg/bw for protein.
A minimum of four meals a day are also the current recommendations for Brad Schoenfeld and Alan Aragon in which they concluded that to maximize protein synthesis, one should consume protein at a target intake of 0.4 g/kg/meal across a minimum of four meals to reach a minimum of 1.6 g/kg/day.(19) Protein should be distributed evenly throughout the day.
Lower dosages of protein followed by higher dosages of protein at night have been found to result in subpar muscle hypertrophy and protein synthesis compared to protein evenly distributed throughout the day.(20, 21)
So before you go looking to see if chili peppers boost metabolism for weight loss or green tea extract, make sure you are following a high protein diet plan, getting 8-10 hours of sleep, performing resistance exercise with lots of compound movements to increase muscle mass (i.e., squats and bench press burn more calories than single joint exercises like leg extension and pec deck).
INTERMITTENT FASTING KEY POINTS
- There is no metabolic advantage to eating small mini-meals when calories are controlled over the day.Intermittent fasting does not slow metabolism.
- It is recommended that a minimum of 3-4 high-quality meals be consumed evenly throughout the day to optimize protein synthesis.
- Studies measuring body composition (DEXA scan), bioelectrical impedance, and other body composition analysis tools have found no meaningful effect on increasing meal frequency and lean muscle/fat loss when calories are equated.
- Intermittent fasting has not been shown to slow down your metabolism.
REFERENCES
REFERENCES
REFERENCES
About The Author
