At 4 months old, your baby may not quite be ready to handle solids but she is gradually approaching that milestone. She has about doubled her birth weight, her stomach has grown a lot since birth and she can handle larger amounts of breast milk or formula at a time, according to BabyCenter.

Bananas are high in potassium and fiber, and delicious in baked goods, cereal, smoothies -- or just as they are as a light snack. To get the best-tasting bananas, always pick those that are firm, free of brown spots or bruises and yellow in color.

Weight lifting is often referred to as progressive resistance training, as you need to increase the resistance to see continued progress. The question of when to increase the weight is a very valid one, but the answer depends on your goals and other factors. Consult your physician before beginning any exercise program.

Eating more ice cream, milkshakes and cookies sure sounds like a good way to put on a few pounds, but it's not the healthiest way to go. These foods may be high in carbs, but they're not the healthy kind.

Compared to younger adults whose main goal is often keeping their weight down, many seniors need to keep their weight up. With age, muscle mass naturally decreases, and appetite reduces, putting older adults at risk of being underweight.

Weight gain can pose as much of a challenge as weight loss, especially if you're naturally very thin or recovering from an illness. And while weight loss and gain plans yield different results, they share some major similarities.

Gaining weight is an important part of your pregnancy. According to W. Allan Walker and Courtney Humphries, authors of "The Harvard Medical School Guide to Healthy Eating During Pregnancy," gaining the right amount of weight will help you have a healthy pregnancy and will help your baby grow and develop right on track.

We all know that too many calories and not enough exercise can lead to weight gain. Over a third of adults in the U.S. are considered obese—the Centers for Disease Control and Prevention says poor eating habits and physical inactivity are mainly to blame.

If you're on the thin side with a weight that's below normal for your height, your doctor may advise you to gain weight. Being underweight can endanger your health and may indicate that you're not getting all the nutrients you need to look and feel your best.

To gain weight, you need to increase the number of calories you consume. Eating or drinking more of high-calorie foods and beverages, such as heavy cream, is one potential way to do this.

A healthy body weight improves immunity, sports performance, healing from surgery or trauma and self-esteem. You hear a lot about losing weight to achieve it, but some people need to put on pounds to raise their body mass index. Frequent snacking and nutrient-rich, high-calorie meals help put on the pounds.

Directing your body to gain fat in a particular area is impossible, because your body has a set pattern for weight gain that's genetically determined. If your arms and legs seem disproportionately thin, fill them out with healthy muscle tissue, rather than fat.