Other seafood sources for high iron and B12 include oysters, trout, salmon and haddock. For people over 50 who must limit saturated fat and cholesterol, seafood sources make superior choices to meats for building up your blood.
More specifically, sedentary men ages 19 to 30 need 2,400 to 2,600 calories; 31- to 50-year-old men require 2,200 to 2,400 calories; and sedentary men over the age of 50 need 2,000 to 2,200 calories each day to maintain a healthy body weight.
As many as you want. Generally, people need about 2000 calories a day. Don't obsess over calorie counts, because it isn't very important to eat the right number of calories as much as it is to eat fruit, veggies, and to cut back on sugar and carbs.