I've got this friend who's always been a bit heavier, but loves to run. He trimmed down to a decent weight a couple years ago, but got into a habit of eating where he'd only eat once a day. Naturally, he ballooned back up.
I was having dinner with him and some other friends tonight and he was talking about how he'd only eaten a house salad all day. Being aware of the need to eat protein-rich, veggie-filled, low-carb meals every few hours, I opted to give no real response. He made fun of me when I ordered a chicken salad because I'm trying to avoid starchy carbs most of the time. He went on about how fat is what makes you fat, not carbs. He mentioned probably 60 percent of his diet right now is carbs. Never mind he's tipping the scales in at 240 at 6-foot right now. Even though he's lost 15 pounds under this diet, it's mostly because he's just drastically reduced calories beyond a sustainable amount.
He's a great guy, so I try to just avoid such conversations. I know I'm carb intolerant and so are a lot of people. I've just been able to come to terms with it and adjust my typical diet accordingly. Many people I know, on the other hand, continue to be fat as they monitor their fat intake while completely overlooking carb intake.