Which group requires the most calories per day

Nursing women.

Athletes.

Pregnant women.

Explanation:

These three requires the most calories per day among the options because their body used tons of energy in daily routines. Nursing women have to breast their child, who drains calories from them basically, because the baby also needs calories to maintain homeostasis. Similarly, pregnant women need to ingest calories for them and the baby, which demand a decent amount because is constantly growing.

At last but not least, athletes are the third group of people that need high calorie diets because they constantly perform intense activity in the sport, which requires a lot of energy produced from glucose and calories.