I think what he's saying is his family is probably fat but always shamed him for it while continuing to eat like shit or buying shit food, then when he asked for "healthy" food they shamed them. I grew up fat and I knew any attempt to lose weight or eat better or exercise would have been met with rigorous shame from my also obese sister and my mom, who bounced around in weight but shamed us both while buying shit food and telling us it was genetic.  He's definitely stupid about weight loss, but obesity is often perpetuated by bitter disgusting parents.