Concernd sister, need advice

Kimmie

So my little brother (24yo) has always been a big boy. Hes 6’8’’ and has always averaged 250-280 lbs. well recently hes quit his factory job and got a in home care job, that doesn’t require much physical activity. In roughly 3 months hes probably gained about 50lbs, and im starting to get concerned for his health. The other day he walked from his house to my house (roughly a block and a half) and he was so out of breath, it was if he just ran a mile. Hes been complaining about his limbs going numb, and he gets cold very easy now a days, and Im worried he may be diabetic or have blood pressure problems or something, but he refuses to go get checked by a dr. (I think hes scared of what they will say) ive tried to get him to go but he just gets mad and quits talking about it. Ive also suggested he start eating better but doesnt seem interested. I need a different approach or a way to smack him back to reality because I only see it getting worse from here. Ive even went as far as making him healthy yummy foods and taking it to him for supper and he barely touches it.