If we had a drug that increased caloric expenditure by 5 calories but increased hunger by 500 calories, so that on average people who took it gained 10 pounds.

If we had a drug that increased caloric expenditure by 5 calories but increased hunger by 500 calories, so that on average people who took it gained 10 pounds. Would you say this drug helped you lose weight? Or on the other end if you have a drug that decreases caloric expenditure by 5 calories but decreases hunger by 500 calories would you say this drug helps people gain or lose weight? We can look at these interventions through the very narrow lens of thermodynamics and say the first one will help with weight loss and the second will help with weight gain. Or we can just give people the drug and see what happens to their weight. It seems very clear to me the second approach is a better one.