Some bacic facts about weight gain

If you eat more fat or sugar than you need for basic physiological processes, for the maintainance of body temperature and for your activities, the body must somehow handle this extra input. One way this is done is by increasing the basal methabolizm to yield heat. Another way is by storing the material taken in as fat.

Normally a person is capable of increasing the basal metabolism to some extend so that a moderate over-consume will not result in excessive fat deposits. The extra intake of fat and sugar is simply burned away. However many persons have only small abilities to increase their basal methabolism after an extra intake of energy-rich meals, and will gain weight from any amount of extra intake.

Obesity is therefore generally either caused by an decreased ability to burn away fat, that is a decreased basal metabolism, or by a habit of consuming more sources of energy like fat and sugar than their metabolism can handle. Also people with normal levels of metabolism will gain weight if they habitually eat in excess of a ceratin amount.

Ecery person has a set of regulatory mechanisms that tend to keep the weight at a certain level. By many obese pesons this mechanism is et to a wrong value so that any weight loss to reduce the obesity will be couteracted by several physiological mechanisms. The hunger will increae so that the person eats more again. The basic metabolism will decrease. The person will feel more tired and thereby reduce his activity level.

One regulatory mechanism that secures that homeostais is the hormone leptine that is secreted by fat cells. The fuller the fat cells are, the more leptine is produced. The leptine reduces hunger and increases basal metabolism so that more fat is burned.

Hormonal disturbances as cause of obesity

A possible cause of obesity and low basal metabolism is reduced secretion of the hormone thyroxine and other hormones from the thyroid gland, because these hormones regulate and mostly increase the basal metabolism.

The hormone insuline stimulates storing of fat and decreases burning of fat and carbohydrates. Person consuming much carbohydrates, and especially carbohydrates with a high glycemic factor, that is those that rapidly is taken up in the blood, will secret more insuline. Thereby the metabolism is reduced and more fat go into the fat cells.

Diebetic persons tend to get obese. A person with dianetes type 2 do not react enough upon insuline secreted. The pancreas gland will often counteract the lack of reaction by secreting even more insuline. The high level of insuline will then lover the metabolism  and therby lower the burning of fat. By treatment of diabetes type 1 and somtimes also type 2 with insuline, the furnished insuline amount can often be constantly too high. Then the body will react by burning less fat and by storing more fat in the fat cells.

Fat tissue makes a hormone called leptin, and fat tissue satisfied with enough fat stored makes more leptin than unsatisfied fat tissue. Leptine reduces appetite and increases burning of fat and sugar and thereby regulates fat deposits to certain levels. Some individuals make too less leptine and this results both in over-eating and reduced burning of an eventual  excessive energy intake. Some of these indivioduals seem to have a genetic defect. The low level of leptine production will set the body weight homeostasis to a too high level and thereby make it difficult to loose weight and remain

Other possible causes are lack of vitamins and minerals, like vitamine B6 ( pyridoxine ), magnesium and chromium, or a wrong mix of fatty acids in the diet, with too low content of essential unsaturated fatty acids.

Automatic physiological effects counteracting slimming

When a person tries to slim off the fat, the body may lower its metabolism even more, making it difficult to take off fat.

This is partly a kind of defence mechanism against starvation that was of use in earlier days when the food supply was unsecure. But it also is due to lack of nutrient caused by the slimming process.

The mechanism is partly an automatic slowdown of the basal metabolism, and partly caused by an increased feeling of being tired, so that one decreases one's own activity level.

Another cause of this effect is that When the food intake is lower, the body gets even less of some essential nutrients that it needs for its metabolic activity. Then the burning of fat will decrease.

Changes in the bodily constitution when a person gets obese

When a person gains weight, this is done in three ways. It partly happens by filling the fat cells by fat, partly by filling the fatty cells with water and partly by increasing the number of fat cells. An increase in number of fat cell occur especially in children and teens that get obese, so that childhood obesity gives a solid foundation for permanent obesity in adult life.

The proliferation of fatty cells most easily happen in early childhood, in the puberty and if the gaining of fat is very rapid.

The increased number of fat cells is difficult to get rid of, and since each cell tend to take up fat and protect the fat from being broken down, those cells make it difficult to slim away the excessive fat again. These cells also acts like a sack with a certain volume, and when the fat goes out, they tend to be filled with water instead. By the slimming process, the cell membranes of the fat cells need a period to shrink, so they cannot contain so much water any more, before essential weight reduction occur.

By knut Holt