So here's the thing: Not often. Maybe. Very correct. Correct. Absolutely wrong. Correct. Correct.

Diet as a noun is one of the most important things in a human's life. Your meat carriage is a machine that needs fuel as well as a whole lot of other things to keep it from breaking down.

Diet as a verb should be very transitory, because by definition diet as a verb is clearly not a stable state. I work out a hard-core gym and this morning I had a post workout chat with a couple of guys I really like. One of them talked casually about losing 24 kgs (roughly 20% of his body weight) for his last competition. Dude looks like a fitness model, but you don't have to watch "Shindler's List" to know dropping 20% of your body weight ain't healthy.

Overweight or underweight, a sustainable, healthy, individual diet (noun) and exercise - will help.

As long as you aren't anorexic or very overweight, body positivity is great. Some people are happy and like being thin, some being fluffy. Beauty is in the eye of the beholder and all.

But if you have no underlying genetic health issues, are younger than about 80 and get winded going up a flight of stairs, then fat or thin you're not in good shape.