Infrequent bowel movements and excess body fat often go hand in hand, so it may seem logical to assume that they are related. But while there is often a correlation, neither condition causes the other.

Approximately 2 percent of people in the United States are underweight, and some of these people have trouble gaining weight no matter what they try. You could be one of these people, or you could be underestimating how many calories you're burning during the day or overestimating how much you're really eating.

You can use many different training methods to build muscle. Pyramid sets, drop sets, straight sets, and wave loading are all very popular and can enable you to put on muscle.

Working with genetic and environmental influences on the body's internal clock, the hormone melatonin regulates daily biological functions of sleep, immune function and metabolism.

If you’ve been through a long illness or a period of emotional stress, your clothes may be baggy, and your family and friends might comment on how gaunt you look. A body mass index below 18.5 is considered underweight -- a condition that can affect your overall health.

Your baby just won't eat. He's not interested in his stage 3 baby food. You try some solids, but he has little or no interest. You know that weight gain slows down at around the nine-month mark, but you wonder how much is too slow. You wonder if he is just finicky, and the problem will correct itself in time.

Whether it's because of an illness or stress, not having the desire to eat can be troublesome if it leads to unwanted weight loss. Unfortunately, there are no foods that are going to make you want to eat more. If you're struggling to eat enough, there are a number of strategies that may help you pack in more calories.

While doctors recommend aerobic activity like walking and swimming to aid your weight-loss efforts and improve the function of your heart, strength training helps you gain muscle mass, or muscle weight, that normally decreases as you grow older.

Volleyball is a game of precision, power and teamwork on the court. For the most powerful setting in volleyball, it is common to tape two of your fingers together for added support and strength, which is a technique known as "buddy taping."

Cake mixes that bake up light and fluffy often include less fat and sugar and greater amounts of baking powder. Less fat and sugar mean a reduction in the weight, or denseness of the cake, while the leavening properties of baking powder increase the volume of a cake mix as it bakes.

You’ll see Ashwagandha in muscle-building formulas, though the herb’s main use is as an adaptogen, similar to ginseng. Adaptogens are purported to help your body deal with stress, whether it be physical or mental.

Poor dietary habits, medical conditions or excessive exercise can cause you to be underweight. Anorexia and bulimia nervosa are eating disorders most commonly associated with being underweight. Being underweight can cause fatigue, osteoporosis and irregular menstrual cycles in women if left untreated.