That sort of impotence is the best indicator of heart disease. They don't need Viagra; they need to stop eating so much fat sugar and carbs.
Fixed it for you.
Fat doesn't necessarily make you fat. It makes you feel full, so you stop eating. Carbs and sugars make you crash and eat even more. Plus they put your body into an emergency mode to deal with blood sugar by converting it into fat.
People need to skip the high fructose corn syrup-laden beverages, the bun and the french fries -- not the burger, the bacon, or the real cheese made with whole milk.
The proof is when people switch to low-carb diets they tend to lose weight, and they don't crash anymore and have more steady energy all day long. Of course, eventually you plateau because protein, carbs, and fat can all be converted to energy (and hence, fat). Calories are also an issue.
In the end, you have to take in less calories than you burn or you're going to gain weight. But regulating blood sugar (by avoiding foods with a high glycemic index) and avoiding blood glucose spikes certainly doesn't hurt.
Matthew