I eat breakfast twice (yogurt and protein powder 24g), before working out and after (cereal and milk and banana), I eat lunch (two carbs, like beans and rice, or potatoes and veggies, meat), afternoon snack (sandwich and apple and banana), and dinner (pasta and meat), and often still feel hungry. I went to the nutritionist who calculates that I probably burn around 3000 calories a day and only eat 2500 or so, so added and extra protein shake. I also snack on a lot of cereal, like cornflakes or cheerios. Regular diets, like on the boxes of food that we buy, are for 2000 calories a day...triathlon training burns way more than that. When I don't eat well, I get fatigue and colds.