Marginal effects can add up quite quickly over a lifetime. Take someone 100 pounds overweight. That is 350000 Kcal more consumption in their lifetime than the

Marginal effects can add up quite quickly over a lifetime. Take someone 100 pounds overweight. That is 350000 Kcal more consumption in their lifetime than they should've had. Let's spread that over 10 years, or 35000 Kcal a year. That works out to about a 100 Kcal difference per day. Over 20 years, it would be about 50 Kcal. Now, they could've made different choices, and there are some people who stay a healthy weight by making different choices. But I would not dismiss small changes as being irrelevant because given the time scale, those changes do add up.