[A] Basically wether you gain weight or not depends on the three following formula:
- Calories in Food> Calories Used = Weight Gain
- Calories in Food you eat < Calories Used = Weight Loss
- Calories in Food you eat = Calories Used = Weight Control
Physical activity is important for physical health, emotional well-being, and achieving a healthy weight. Physical activity may help you control your weight by using excess calories that would otherwise be stored as fat. Most foods and many beverages you eat and drink contain calories, and everything you do uses calories. This includes sleeping, breathing, digesting food, and of course, moving around. Balancing the calories you eat with the calories you use through physical activity may help you maintain your current weight.
[B] Your weight is determined by several factors including :
- your genetic background
- your eating habits
- metabolic rate
- your general activity level.
Your Genes influence your body weight by setting basic parameters on your body's metabolic efficiency (the efficiency with which your body burn calories). Fatter people tend to have very efficient metabolisms; they require less fuel to run than thin people, and store excess fuel in the form of fat. Genes governing metabolism run in families. If one of your parents is obese you are several times more likely to be obese yourself than someone who doesnt has parents of a healthy weight. If both of your parents are obese you are at a very high risk of becoming obese yourself. As powerful as they are, your genes only determine a tendency towards higher or lower metabolic efficiency; they do not by themselves determine what actual body metabolism will be. Lifestyle choices such as exercising also influence a person's metabolism and thus their weight.
Apart from genetics, your metabolic rates are largely determined by how active you are. We are told that for every ten years beyond our early to mid-twenties our metabolism slows about 10%. While a reduction in metabolism is observable as we age, such a reduction may be more due to a sedentary lifestyle than to mere aging. Muscle tissue is metabolically active compared to fat, and thus our metabolic level at any moment is in large part due to the state of our muscle mass. Inactivity accelerates loss of muscle tissue over time which decreases metabolism, making it all but certain that weight will be gained. Activity, on the other hand, reduces muscle loss, or even increases muscle mass, with the effect of increasing metabolism and making it easier to lose weight.
Your food related habits and cultural expectations are also important determinants of your weight, influencing the types and amounts of foods consumed. For instance, families favoring high-fat, high calorie food (such as lasagna) served 'family style' (so that anyone can take as much as they like) are at greater risk for eating too much food and gaining weight than families serving smaller portions of lean meats, steamed vegetables and brown rice. Similarly, families who push members to eat, or who keep high fat snacks and deserts handy are at greater risk for weight problems than are families that promote sensible portion sizes and save treats for special occasions. The speed at which people learn to eat and the consciousness with which they do so are important too. People who eat quickly tend to eat more than people who eat slowly as it takes a few minutes for your stomach to tell your brain it is full. Fast eaters sometimes finish their plates before getting the stomach's fullness message.
