Originally Posted by ReillyJ
I understand the definition of "diet" is more correctly to describe one's food intake but i don't think the average person thinks of it in those terms which is why i don't use it w/others.
Maybe this varies regionally, but this isn't my experience. I find that most people do use and understand diet as a generic term. I hear people (thin people too, not just overweight people) all the time talking about diet in the generic sense:
"I'm concerned about my five year old's diet, I can't get her to eat any vegetables."
"I need to reduce the amount of fat in my diet, my doctor is concerned about my cholesterol."
"My diet would be a lot healthier if I didn't like fried foods so much.
"Now that I'm diabetic, I have to watch my diet more carefully."
"If you want to bulk up, you need to weightlift and add extra protein to your diet."
Context tells you how the person means it.
"On a diet," or "dieting" is generally weight loss. "On a special diet," or "my diet" could mean anything, but usually you can tell what the person means by how they use the term. Within a sentence or two you get what they mean.