Junk food companies love the concept of “moderation”.

Some of them (e.g. the Sugar Association, Snack Food, and Grocery Manufacturers Associations, with members as Coca-Cola and Hershey), adopted the motto: “All foods fit in a balanced diet", to give the illusion that your diet is not unhealthy if it includes their foods.

...for sticking to healthy diets easier. 

Nutritionists mean by moderation small portions, especially when talking about food that we should not eat. This means that eating a little bit of bad food doesn't have to ruin your diet or make you feel ...