I'm old enough to remember the 70s when most people were relatively slim. That's not the case anymore especially in the West. Even in Asia, where most people are smaller, obesity is a major issue amongst the better off and diabetes is rampant.
The sugar industry made huge efforts to divert attention from sugar to fat throughout the 80s and 90s. The scientific concensus seems to be that the main culprit is added sugar and refined carbs.
So far the political feedback has been marginal. When a friend of mine became an MP 9 years ago I tried to encourage him to make introducing a sugar tax on soft drinks his issue. He didn't sadly but eventually the UK has woken up gradually to reality and introduced one. It's really too little, too late and it seems to me the world is on the precipice of a sugar induced heath disaster.