Beauty, like fashion, is a learned concept, and the notion of beauty changes over the years. By today's standards, Marilyn Monroe would be considered "overweight".

The leading sex symbol, Lillian Russell, weighed over 200 pounds, at the turn of the century. Our society accepts underweight people, rather than the obese, which tend to be looked as 'lazy' and 'weak-willed'.

This obsession with weight gain is growing to be another headache, with teenagers starving themselves for the "waif like" look and losing their health in the bargain. Most people who gain weight are taking in more calories per day than they are using.

If there is unexplained weight loss, despite eating the normal calories and maintaining the usual physical activity, then there could be a medical problem that needs attention.

Factors of rapid weight gain

One of the factors of rapid weight gain could be hypothyroidism, in which a thyroid hormone deficiency affects the metabolism of food and the way it is digested, thus leading to weight gain. Symptoms like fatigue, coarse skin, swelling of the face, herald this condition.

Unexplained weight gain could also be caused by Essential Fatty Acid Deficiency, in which the essential fatty acids in the body that it needs for making hormones to maintain the body's metabolism system.

The deficiency of these leads to food cravings and that too especially for fatty foodstuff and the symptoms to watch out for is dandruff, dry hair, arthritis problem, diabetes etc.

Weight gain causes can also be food sensitivity, which happens to individuals with sensitivity to certain kinds of foods, which cause fluid retention and increase body weight. The person who is food-sensitive must avoid all such foods.

Signs include are headache, fatigue, depression, pain in joints, sinus problem, among many others. Weight gain tips for the underweight Weight gain tips for the underweight include eating foods rich in omega-3 essential fatty acids, like salmon, tuna, walnuts and flax; carbohydrates from whole grains, fruits and vegetables and proteins from sources like lean meats, fish, poultry, nuts, seeds and legumes and not to stock up on junk food that contain unhealthy trans fat.

To gain weight and be at the same time, fit and healthy one needs to consume more calories every day from healthy foods and choose the right types of exercise to build more muscle than flab tissue.

One must learn to stop weight gain and maintain a body weight to stay fit in body and mind, as both underweight and obese conditions are not desirable.