My ideal type of elite soldier can deal well with fasting; no need for breakfast or lunch, things which slow you down.

Also, assuming that we want to forge the most elite soldiers, we should feed them the most nutrient dense meats known to man. Ideally 100% grass fed meat, the finest cuts of beef. Beef ribs, beef neck bone, beef liver, beef large intestine, etc.

Also, what not to feed them, or what not to let them consume. From what I understand, the military is insanely strict when it comes to scheduling, fitness, working out, etc., but from what I understand, the food and beverage situation is horrific. Why allow them consume sugary monster and rockstar energy drinks? Only allow them to drink black coffee.

Also, do not allow them to eat sugars, starches, or anything which increases their body adipose tissue. Only build muscle.

Furthermore, weight lifting. Insanely heavy weight lifting is the goal.