If you want to incentivize the lowest-cost option, you should be pushing for hydrogenated saturated fats and high-sugar diets and for people to take up smoking. Morbidly obese people tend to die quickly from cardiovascular failure in their 60s and end up costing substantially less than the ordinary population in health care costs over the course of their lives since they don't live to be octogenarians. Especially healthy, smart-eating, athletic people are actually the group that costs the most in total healthcare.

https://pubmed.ncbi.nlm.nih.gov/18254654/ "Because of differences in life expectancy, however, lifetime health expenditure was highest among healthy-living people and lowest for smokers. Obese individuals held an intermediate position."

"Although effective obesity prevention leads to a decrease in costs of obesity-related diseases, this decrease is offset by cost increases due to diseases unrelated to obesity in life-years gained. Obesity prevention may be an important and cost-effective way of improving public health, but it is not a cure for increasing health expenditures. "

The linked article was published in PLoS Medicine, a high impact-factor journal.