Hard to imagine that a 24 rack of coca cola is actually cheaper than an iodine tablet or a couple drops of household bleach or you know, boiling water.
It can be when you don’t have access to boiling water, bleach, iodine tablets, and/or the water you have access to is extremely contaminated with chemicals because of pollution.
Obesity is much more related to the type of food than the quantity.
Many developing countries have obesity issues due to scarcity of fresh and healthy food.
In some places coca cola is cheaper and / or more available than drinking water.