Obese people won't get on a bike, though, because it's too big of a step. An ebike is a decent gateway into weight loss.

Exercise is for health, diet is for weight loss. The overlap exists but is minimal. Exercise activity hermogenesis (often known as EAT, ironically) is usually estimated to be around 5% of total daily energy expenditure (TDEE).

I wouldn't be surprised if the obese people in question started to exercise and actually increased their food intake to match.