I’ve just attended a conference on preventing chronic disease, and something that appealed to me greatly was the idea that at all formal dinners (and my how I’ve suffered from formal dinners over the years) the main choice would be vegetarian. You’d have to request meat. The idea came from Susan Jebb, Head of Nutrition at the Medical Research Council.

How many people would request meat? Not many, is my bet. Many would just never get round to it, and others would feel slightly awkward asking for meat. Meat eating is, after all, one of the main factors destroying the planet as well as giving us chronic disease. I’d never have the nerve to ask for meat even if I was hungering for a rare steak dripping with blood, something I love.

Such a change would be a perfect example of “nudge economics,” whereby the healthy option is presented as the main option, and you must opt to get the unhealthy option. Richard H Thaler and Cass R Sunstein describe “nudge economics” in their book “Nudge: Improving Decisions About Health, Wealth, and Happiness.”

You could, of course, do the same with all courses. Vegetable soup for the first course or maybe no first course at all unless people asked for it. Fruit salad for desert, and perhaps an expected 500m walk between courses unless people opted out.

Richard Smith is a doctor, editor, and businessman.