Especially beware of calorie - dense foods which contain huge amounts of calories even though you get very little food. (fitbodyhq.com)
These foods were easily stored, contained huge amounts of calories for their size and were able to support large populations living in smaller quarters. (mindbodygreen.com)
Because their metabolism burns up calories very quickly, they have to consume a relatively huge amount of calories to gain weight. (fitnessandpower.com)