Obesity is caused by lack of access to quality food, being too scarce or too expensive. Sugar and fats are cheap, so most of the pre-made foods are just that. So increase the quality of the food available to the masses and do proper education regarding nutrition and healthy living, and the obesity rate will decrease.
Most of the obese people are like that not because they choose, but because they cannot do better.
What you see there is the result of impacts over many/many years. A human lifespan is just a blip on that scale. And Mars surface is huge compared to that of a human.
It is more lucrative for interested parties (read that politicians) to spend money on military than on healthcare. Or education. Or environment protection.
It's a good idea to have a list of must have's/nice to have supplies for the baby. Stick to the must have's, skip the others. You will spend less money and avoid having too much stuff afterwards.
The money you save this way you can use it as a buffer for the periods with limited income.