the doctor just told you to lose weight but you know you're healthy  Yeah, well, just feeling fine does not tell you anything about your health. There are many medical conditions that are not discovered until they become fatal. Some people riddled with cancer don't even know about it until they're on their deathbed one day. My family friend's son, 10-11, had some pain in his leg when playing soccer, died 2 weeks later. Doctors didn't even try to do anything for him, there was no point. The human body is an amazing machine. At 20-30, you're not supposed to be worried about blood pressure, cholesterol, joint pain, heart problems, etc. Oh, your blood pressure is fine, therefore you're healthy? No, you're healthy because you're 21. You can do all kinds of horrific abuse to your body, and be totally fine while it's young and resilient. How many old obese people do you see in nursing homes? How many fat people celebrate their 100th? Fatties can be all smug and dismissive of their doctors and medical science, until they hit 30 and start having heart attacks and riding mobility scooters, huffing and puffing their way through life.