Body weight | physiology | Britannica (original) (raw)
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influence on aging process and life span
In aging: Species differences in longevity and aging …with life span: brain weight, body weight, and resting metabolic rate. The dependence of life span on these traits can be expressed in the form of an equation: L = 5.5_E_ 0.54_S_ −0.34_M_ −0.42. Mammalian life span (L) in months relates to brain weight (E) and body weight (S) in… Read More
percentage of water
In human nutrition: Water …50 to 70 percent of body weight, approximately 60 percent in healthy adults and an even higher percentage in children. Because lean tissue is about three-quarters water, and fatty tissue is only about one-fifth water, body composition—the amount of fat in particular—determines the percentage of body water. In general, men… Read More
significance in boxing
In boxing: Weight divisions …contestants’ having to concede excessive weight to their opponents. Some of these weight divisions originated in the United States, others in Great Britain. Read More
affected by
anorexia nervosa
In anorexia nervosa …individual to maintain a normal body weight. A person with anorexia nervosa typically weighs no more than 85 percent of the expected weight for the person’s age, height, and sex, and in some cases much less. In addition, people with anorexia nervosa have a distorted evaluation of their own weight… Read More
In mental disorder: Eating disorders …of a considerable loss in body weight, refusal to gain weight, and a fear of becoming overweight that is dramatically at odds with reality. People with anorexia often become shockingly thin in the eyes of everyone but themselves, and they manifest the physical symptoms of starvation. Bulimia nervosa is characterized… Read More
In mental disorder: Eating disorders …a failure to maintain normal body weight for an individual’s age and height; weight loss is at least 15 percent of the ideal body weight. Weight loss occurs because of an intense desire to be thin, a fear of gaining weight, or a disturbance in the way in which the… Read More
exercise
In exercise: The effect of exercise on coronary heart disease risk factors Excess body weight is considered by most experts to be an independent risk factor for coronary heart disease, although obesity also indirectly increases the risk via deleterious impact on blood pressure and the lipoprotein profile. Exercise habits are strongly related to body weight. In virtually all… Read More
human growth and development
In human development: Types and rates of human growth …tissue (that of the skeleton; weight is a mixture of all tissues, and this makes it a less useful parameter in a long-term following of a child’s growth). In this section, the height curves of girls and boys are considered in the three chief phases of growth; that is (briefly)… Read More
nutrition and exercise
In human nutrition: BMR and REE: energy balance …over time one will gain weight; insufficient energy intake results in weight loss, as the body taps its energy stores to provide for immediate needs. Excess food energy is stored in small amounts as glycogen, a short-term storage form of carbohydrate in muscle and liver, and as fat, the body’s… Read More
pregnancy
In pregnancy: Weight The early part of pregnancy usually is accompanied by moderate weight loss caused by the woman’s lack of appetite and in some cases nausea and vomiting. Between the third and the ninth month of pregnancy most women gain about 9 kilograms (20 pounds) or… Read More
