[ The Green Leaf ]

What is obesity causes?

Most researchers agree that a combination of excessive calorie consumption and a sedentary lifestyle are the primary causes of obesity. The other causes are :

Environmental Factors

Environmental factors that very closely correlate with an increased risk of obesity are increased food consumption/ fast food, and sedentary lifestyle. Obese people are less active than those of normal weight. Physical activity of human is decreases so all the calories our eat are not utilized, or burned off. It stored as fat tissue, which can lead to weight gain.

Genetic factors

1. Inherited genetic variation is an important risk factor for obesity. Evidence from twin, adoption and family studies strongly suggests that biological relatives exhibit similarities in maintenance of body weight. Genetic factors also are beginning to be implicated in the degree of effectiveness of diet and physical activity interventions for weight reduction.

2. Obesity is the result of interplay two kinds of genetic effects, there are the additive genetic effect and the genotype-environment interaction effect.

3. The additive genetic effect in amount of subcutaneous fat is quite low but that it is higher (around 25 to 30 per cent) for fat mass and regional fat distribution. These results suggest that visceral fat, perhaps, is more influenced by the genotype than subcutaneous fat.

4. a genotype-overfeeding interaction component exists for body fat, which suggests that sensitivity of individuals to changes in body fat following overfeeding are genotype-dependent.

5. one finds a slight genetic effect for the proportion of protein, fat, and carbohydrate in the diet. (Physical Activity Sciences Laboratory, PEPS, Laval University, Sainte-Foy, Québec, Canada)

Psychological factors

Obesity can be caused by psychological factor, studies have found some people eat more when they are affected by depression, anxiety, binge eating, or other emotional disorders.

Illness

There are some Medical illnesses that can increase obesity such as hypothyroidism (poorly acting thyroid slows metabolism),Polycystic ovary syndrome, cushing's syndrome,growth hormone deficiency,the eating disorders, binge eating disorder and night eating syndrome, depression, and etc.