Studies have shown that people may not need to use stuff like Phentermine 37.5 and other weight loss products if only they were trained to eat single-serve portions, or snack sizes. They said that people who have been given single serve chips or whatever else are more likely to get the same amount from a big bag than those who have been dipping their fingers in big bags from the start.
This is particularly important for parents to know. Sometimes, because of the savings, we always opt for the family-sized portions but also end up buying more of these. Our kids then don't learn to only eat their portion size, they learn free rein on food.
Case in point: my parents would often give us say, a piece of candy each. Or we would divide a whole pizza for the whole family. We'd have a limited smount of food that is ours. My husband's family was different. They would buy three or more family sized pizzas so that everyone can eat to bursting. MIL would buy packs and packs of candies or bread or fruit or sodas. No one need learn to really share or exercise portion control because there's just real plenty for everyone. What happens though is that some food end up being half eaten because a person was actually already full but there was just all these food around beckoning him to eat. And hubs' family is generally overweight.
Parents need to teach their kids to learn when to stop eating and wait for that feeling of fullness, instead of waiting for that feeling of fullness while continuing to eat. It is not only important for kids to learn the value of temperance, it is also important to their long-term health.
Of course, there are things we should buy in bulk because we use them often, like milk. But especially for junk food, best to keep things snack sized.