Your body weight depends on a simple equation: Weight change equals calories in minus calories out. Burn as many calories as you take in and your weight will remain the same.

Just like losing weight requires a reducing the number of calories you eat, gaining weight in the form of lean muscle tissue requires consuming more calories. Getting enough calories of the right types will fuel your body with the nutrients it needs to build and repair muscle tissue damaged during your workouts.

Drinking plenty of water is a healthy way to boost your metabolism and stay well-hydrated. Your body will burn extra calories processing the water, and drinking enough can help you achieve your weight-management goals.

Coke and other carbonated colas are deeply embedded in American culture. You can buy a cola at almost any employee break room, convenience store or restaurant. Although colas are popular, they're also high in calories and devoid of helpful nutrients.

While a small cinnamon roll can be relatively easy to fit into a healthy diet as an occasional indulgence, the extra-large, frosting-covered options can contain almost half of your daily calorie allotment. A mini roll can give you a taste of this treat without all of the calories.

Calories refer to the amount of energy released by food, which is determined by the content of carbohydrates, protein and fat. You can either use that energy through physical activity or the body stores it in the form of fat for future use.

Even with no physical activity, your body burns calories to fuel normal functions such as breathing and pumping blood. The number of calories you burn in a day of total rest is called your resting metabolic rate, or RMR, and you can estimate it using a mathematical formula.

Maintaining a healthy weight requires balancing calories consumed with calories burned. A 10-year-old girl needs enough calories to support growth and provide energy. The exact number of calories a girl needs depends on her activity level.

With no added ingredients, popcorn is a low-calorie food that's high in volume to fill you up without compromising your diet. The calorie count rises, however, when oils and butter flavorings are added, as with standard microwave popcorn.

Compared to other mixed drinks, gin and diet tonic is a sensible option if you're watching your caloric intake. Still, alcoholic beverages are best consumed in moderation, especially if you're watching your weight. The calories are "empty,"

A study published in "Stroke" in 2011 showed that over a period of 10 years, people who ate more white fruit like apples, pears and bananas had a lower incidence of stroke than those who ate more of other colors of fruit. Apples and pears were the most commonly eaten white fruits in the study.

Avocados are packed with nutrients like fiber and vitamin K, but they're also much higher in calories than most other fruits.