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.
Recommended daily calorie intakes vary across the world. According to the National Health Service (NHS), UK, the average male adult needs approximately 2,500 calories per day to keep his weight constant, while the average adult female needs 2,000. US authorities recommend 2,700 calories per day for men and 2,200 for women. The NHS stresses that rather than precisely counting numbers (calories), people should focus more on eating a healthy and well balanced diet, being physically active, and roughly balancing how many calories are consumed with the numbers burnt off each day.