Metabolic 'economy mode'
Resting energy expenditure
Gaining or losing weight depends on balancing the amount of calories we eat and the amount of calories we spend. Due to a their ADRB2 gene makeup, some individuals are very efficient in conserving energy, making it harder for them to lose weight.
This might be a reason behind your difficulties to lose weight. Get GeneInformed, and we could check this for you. We will provide you with the best-suited steps to suit your ADRB2 makeup.
When energy intake exceeds energy expenditure, weight gain occurs. However, the amount of weight gained varies among individuals. Genetic factors can influence the amount of weight gained with overfeeding.
60% to 70% of the total number of calories we burn is for the basic actions our body takes to sustain itself- normal cellular and organ function under resting conditions. This is called the Resting Energy Expenditure (REE), and it plays a significant role in weight control.
REE estimate the number of calories you burn at rest. It includes your Basal Metabolic Rate (BMR), which measures the number of calories you burn maintaining your basic functions, such as breathing, circulating blood, growth and repair. In addition to the BMR, REE also includes the number of calories burned for conducting small amounts of activity.
Gene: BETA-2-ADRENERGIC RECEPTOR (ADRB2)
Genomic coordinates (GRCh38): 5:148,826,592-148,828,633
ADRB2 is a gene involved in the regulation of energy expenditure. Expressed in subcutaneous adipose tissue (fat cells under the skin), ADRB2 mobilizes lipids (fats) within human fat cells by stimulating lipolysis (fat breakdown).
Experimental studies have shown that the minor ADRB2 variant reduces the function of the receptor it encodes for. This results in a reduced ability to mobilize and break lipids within the adipose tissue. It also promotes a more efficient thermogenesis, which means less calories spent on maintaining body heat.
This ADRB2 makeup reserve more energy by slowing the rate of fat breakdown. In addition, it has a unique response when calorie intake is reduced. When homozygous carriers cut in calorie consumption, their body responds by entering a strict "economy mode", slowing their metabolism to conserve more energy.
Individuals with two copies of the ADRB2 variant show lower REE (Resting Energy Expenditure) (see black column, figure a). Moreover, REE decreases substantially when calorie intake drops (black column, figure b)
To sum it up, ADRB2 homozygous individuals are very good at conserving energy. They spend less energy for their basic metabolism, and promote an even more economic metabolism if under calorie restriction diet.
In order to succeed in losing weight, gradual and constant decrease in calorie intake is preferable. Exercise is extremely important, since other then burning calories it also elevates the Resting Energy Expenditure, and decreases appetite. See customer’s report for detailed recommendation.