Adipose tissue under the skin (subcutaneous) or in the body cavity (visceral) stores fat, with a small amount in our muscles (intramuscular). Body fat serves as an energy depot. When the energy providing substances deplete in your bloodstream, the body detects this and demand from the fat reserve.
Fat storage and energy
Fats are stored as triglycerides in fat cells and are released through the action of an enzyme known as hormone-sensitive lipase (HSL). This allows fatty acids to enter the blood, where they bound to a protein called albumin and enter muscles to be “burned.” “Burning” of fat is also known as beta-oxidation.
ATP produced from the breakdown of fat is used for metabolic processes in the body including breathing, body temperature regulation, digestion, and excretion. We use approximately 70% of the ATP produced from fats.
Excess body fat can negatively impact nearly every facet of life, including:
• Increased risk of organ letdown and Poor circulatory health
• Increased threat of stress fractures
• Decreased mobility
• Increased risk of heart disease, stroke, and cancer
• Decreased sexual and reproductive health
Fat cells can function as endocrine plants and yield hormones that influence key processes in the body most of which lead to more fat accumulation. Beyond the health benefits, having less body fat is often considered more attractive and desirable as the underlying musculature is revealed. Further, carrying a lower body fat is advantageous for many sports competitors (excluding sumo-wrestlers) as extra fat weight adds drag and additional resistance that must be overcome.
Losing these accumulated fats poses a problem, recent developments (bariatric surgery, medications) in obesity treatment have a low success rate (<10 %) for permanent weight loss instead these fats are regained in less than a year. In the United States, around 68% of the population is overweight. Obese children have also doubled since 1980. We need a better solution. Knowing how fat loss works may be helpful. What you should know Majorly, Fat cells store body fat and are continuously turning over. Fat metabolism is regulated by nutritional, metabolic, and hormonal factors; the net effect determines levels of circulating fatty acids and extent of body fat. Fat loss and hormones Fatty acid release and use require lower insulin levels and an increase of the hormones glucagon, cortisol, epinephrine, and growth hormone. These “anti-insulin” hormones activate HSL. The other major hormone that influences fat metabolism is Thyroxin (thyroid hormone). After a large feeding, glycogen is synthesized till stores are replenished. If high blood sugar persists, glucose is converted to fatty acids. Amino acids can also be converted to fatty acids. The enzyme necessary for cells to accept triglycerides is lipoprotein lipase. In the un-fed state, insulin concentrations fall, and the anti-insulin hormones increase. This accelerates fat to use. Fat loss and caloric deficit A significant decrease in caloric intake leads to efficient fat preservation. Since insulin is low, thyroid hormone production decreases; reducing resting metabolism. This takes place within 24 hours of starting an extreme diet. The body’s response to calorie deficiency makes rebound weight gain all but definite once the diet is discarded. Muscle is usually lost, so the body usually becomes fatter. Stages of fuel use during fasting Fat loss is a complex problem With our focus on specific nutrients, intensive nutrition counseling, dieting, and processed food consumption over the past 30 years, body fat levels have also increased. In other words, more information, more dieting, more junk food has given us more fat. While some of this may seem counter-intuitive, it illustrates the importance of body awareness (hunger/satiety cues), avoidance of processed foods, regular physical activity, and influential food advertising. Summary and recommendations To maintain a low body fat and lower body fat: • Dietary fiber • Fruits and vegetables • Sleep 7-9 hours per night • Avoid extreme diets • Low-energy-density foods and dietary protein • Avoiding refined carbohydrates • Adequate hydration While cortisol can break down muscle tissue, it can also break down body fat. If you increase physical activity and nutritious food intake, metabolism will increase. Blaming weight gain on calories is like blaming wars on guns. The diet is not the cause of excessive body fat levels. Rather, it’s the entire lifestyle. Severe calorie deprivation inhibits the production of serotonin, a brain chemical needed to control appetite and maintain harmony with food.