Basal metabolic rate or otherwise basal metabolism is the energy required at rest for vital body functions, like food digestion, body temperature, production of hormones etc.
The total daily energy expenditure is the sum of the energy of basal metabolism, food thermogenesis and energy spent for physical activity. The basal metabolism is the bulk of body’s energy requirements, covering approximately the 70% of the total. It is influenced by a number of factors such as age, gender, hormonal status, muscle and fat mass. Some of the aforementioned factors are modifiable, such as percentage of body fat, muscle mass and dietary factors as diet.
Increase your muscle mass
In order body to sufficiently maintain muscle mass or even build up more muscle tissue, requires a large amount of energy daily. Many studies have revealed that the increase of muscle mass significantly alter basic metabolism. However, since not all of us love exercise, recent researches highlight a new type of physical activity that does not involve exercise. It seems that people who do not play sports but are constantly on the move, have higher metabolic rate and daily energy expenditure, compared to those who are indolent and choose a sedentary lifestyle. Therefore, integrate action in your life, even if you don’t love exercise.
Avoid express hypocaloric diets
Strict low caloric diet patterns even if facilitate fast and immediate weight loss, appear to significantly reduce basal metabolic rate. Human body has survival as a first priority. Extreme diets stress body and cut down basic metabolic rate. In order body to compensate the lack of energy, develop a “resistance” to any weight loss attempt by reducing its daily energy requirements. A similar effect in body metabolism has the so called “yoyo” phenomenon, which is the repeatedly weight loss and weight regain, in a relatively short time. If you want to keep up your basal metabolism, obtain normal body fat and if loss of weight in needed, choose a slow and steady manner, avoiding fast and extreme diet patterns.
Does color of fat matter?
Fat tissue is related with unfavorable effects. Recently the role of another fat tissue has emerged, which seems to participate in basal metabolism. Brown adipose tissue is the main fat mass of newborn children, which gradually is replaced by white adipose fat cells. Many studies have shown that brown fat has a very high thermogenic capacity by increasing the energy expenditure of body. The reason is that brown adipocytes contain much more mitochondria than white adipocytes. A Finland study has shown that the activity of brown adipocytes increase at low temperatures, because is required greater activity in order to maintain the right body temperature. So if you are not afraid of cold, go and have outdoor activities during winter.
Frequent, small and high protein meals
The frequency of meals does matter. Having several small meals during a day (at least 5), seems to positively affect basal metabolic rhythm, as it constantly keep working. Of great importance is breakfast meal, as it seems to be part of the "awakening" of body’s functions and metabolism, after an overnight fasting. People who regularly have breakfast seem to have up to 10% higher basal metabolic rate than those who do not consume breakfast at all. In addition to meal frequency, food composition also seems to affect basal metabolism, through thermogenesis. Among macronutrients, protein requires more energy in order to be digested, transferred and absorbed, compared to other macronutrients. So, start your day with a good breakfast, which contains lean protein products!
Drink plenty of water
Dehydration has been found to negatively affect basal metabolism, by slowing it down significantly. Water is the most important element of body (75%), highlighting the importance of adequate hydration in order to maintain body’s proper function. The minimum daily fluid intake is about 2-3 liters, depending on body mass and daily activities. The fluid intake includes also fluids other than water, such as fruit juices, tea etc.
Time for a good and restful sleep
During sleep, basal metabolism is considered to be reduced by 15%. Our body has a biological clock (circadian rhythm), which coordinates the production and action of hormones as well as several biochemical processes. Many studies have shown that reduced and increased sleep duration adversely affect basal metabolism (U curve). The average adult needs of sleep are 7-8 hours per day.
The role of diet
Many studies have been done in nutrients and how they affect basal metabolism. Certain nutrients, as caffeine, capsaicinoids and catechin, are believed to affect energy expenditure through fat oxidation and thermogenesis. Most of these nutrients have been shown to temporarily raise basal metabolic rate after pro-longed consumption. In specific, studies have shown that capsaicinoids and catechins, which are found in spicy foods such as chili peppers and tea respectively, increase thermogenesis effect of food. There is also evidence which support that catechins alter fat oxidation. Similarly, caffeine consumption increases 3-4% the daily energy expenditure and food thermogenesis.
In conclusion, although health and basic metabolic functions are largely determined by genetic background, there are parameters that we change. So wake up your basal metabolism, by simply adopting a healthy lifestyle!