the city and country getting worse. it s not unreasonable and it s not picking on anybody. reporter: the city health department reports that 58% of adults in new york city are either overweight or obese. among public school children that, rate is close to 40%. soda is a huge problem. reporter: christy is a nutritionist who has been working to reduce high obesity rates in harlem. one big problem she says is healthier food is more expensive leaving people with few options and soda doesn t help. soda has more calories. and the more calories you drink, you don t compensate for them the same way as you do when you eat more calories. reporter: but not all public health doctors are applauding the city s move to ban soda for those on food stamp. if we could and it would work, is it the right thing to do. reporter: is it? i am not so sure. reporter: the doctor is work in harl tom reduce diabetes which is associated with obesity. food stamps pay fos a bucket of junk