The status of people going to hospital is largely irrelevant; the goal should be to ensure that fewer people do. We know that the government telling people to lose weight is not particularly effective, because, again, governments in the developed world have been trying for decades without much success. More direct methods (eg the sugar taxes/minimum pricing that some European countries have introduced) are looking to be a bit more effective, but you're looking at a slow. However, covid vaccines are known to be very effective, and can be given quickly, so encouraging people to get those is appropriate.