metabolism

Metabolism is the process which the body converts food and drinks into energy.  When resting, the body needs energy for breathing, adjusting hormone levels and blood circulation.  The number of calories the body uses to carry out these functions is basal metabolic rate.  Basal metabolic rate is determined by age, sex, activity level, hormones, height, body fat levels, genetics. body size and composition among other factors.

People dont become overweight overnight.  The pounds creep slowly, unnoticed until one day nothing in the closet fits.  Weight gain is most commonly as a result of eating more calories than you burn.  To lose weight, you need an energy deficit by eating fewer calories or increasing the number of calories you burn through physical activity.

Calorie is a unit of energy supplied by food.  Calorie is a calorie regardless of its source.  Calorie balance is like a scale.  Calories consumed from foods and drinks must be balanced by the calories used.

Calorie counting has a number of challenges.  The first one is that the brain regulates body fat levels and it will increase hunger and decrease your activity levels to try and resist any changes. Metabolic rate changes over time and it will drop during long periods of calorie restrictions.  Having to weigh foods you eat means that you wont be able to eat out at restaurants and friends houses.

Insulin hormone is the gatekeeper to the fat cells.  When insulin levels go up, fat cells store fat and ensure that whatever fat in the body does not get out.