Q: I am 75 years old and my doctor has ordered me to put on about 10 pounds (I am very thin and agree I need more weight to be healthier). What are some foods I should eat to gain healthy weight and energy?

A: Gaining weight healthfully is actually trickier than you might think. The object is to make the weight gain mostly lean body mass (muscle) and not much body fat.

You can accomplish this by taking in more calories than you burn, in addition to partaking in a regular aerobic exercise and muscle-strengthening exercise program. (Note that people in your age category benefit highly from a regular program of strength training.)

You will also want to gradually increase your consumption of healthy, energy-dense foods. Keep in mind that you can boost caloric intake healthfully without having to purchase expensive supplements—it just takes a little planning.

What’s more, your age group tends to have a problem getting in enough protein, so you will need to be especially attuned to increasing your intake of higher-calorie (but still healthy) protein sources.

To learn more about which foods are highest in “nutrient density,” you can access the USDA MyPyramid.gov site.

Here are some other suggestions for getting in extra calories:

• Choose larger portions of healthy protein sources: peanut butter or other types of nut butters (a great higher-calorie source of protein and nutrients), low-fat dairy such as yogurt and cottage cheese, nuts and lean cuts of chicken, turkey and fish, such as salmon and tuna.
• Choose higher-calorie juices more often, such as cranberry and pomegranate juice, as opposed to drinking calorie-free beverages like tea and coffee.
• Choose a higher-calorie whole-grain cereal such as Post Grape-Nuts (208 calories in 1/2 cup serving) versus a low-calorie refined-grain cereal such as Kellogg’s Special K (only 117 calories in an entire cup).
• Add generous amounts of healthy fats like olive and canola oil into your day
• Add in a few high calorie snacks throughout the day such as a nutritious shakes or smoothie made with real fruit, fat-free milk, sugar and some added non fat dry milk and even peanut butter to boost calories and nutrient density
• Make sure to eat three meals a day, plus get in those higher-calorie snacks and you should be on your way to putting on some extra weight the healthy way!