EAT frequently. Make time for three large meals and 2 to 3 hefty snacks every day.

Eat larger than normal portions at meals.
Eat higher calorie foods like dried fruit, starchy vegetables, dense whole grain breads and cereals, bean soup and nuts.

Add lots of “extras” to the food you eat like healthy unsaturated fats in olive and canola oil, nuts, seeds, peanut butter and avocados.

Add carbohydrates and proteins from honey, jam,
dried fruit, wheat germ and non-fat dried milk powder.

Take more beverages by drinking shakes, milk and juice, instead of water, coffee, tea and diet sodas.

Do resistance exercises. Weight training converts the extra calories into muscle rather than flab.