Final answer:
Fats should make up 20% to 35% of an adult's diet, particularly unsaturated fats. Proteins are also important, comprising about 15% of the diet, while complex carbohydrates should be the majority at 55%.
Step-by-step explanation:
The nutrient source that should make up 20% to 35% of an adult's diet is fats, with a focus on obtaining most of this from unsaturated fats. Foods that are high in nutrients such as fiber and proteins are considered healthiest, and adults are encouraged to have a variety in their protein sources including nuts, seeds, beans, legumes, and lean meats. Proper nutrition plays a vital role, especially during growth periods such as infancy and adolescence, and for adults, it is critical for maintaining overall health. It is recommended that protein should account for about 15% of total calories, and complex carbohydrates, which bring additional vitamins and minerals, should make up a majority of the diet at 55%. Remember, balance and moderation are key, and it is important to incorporate a mix of protein, carbohydrates, and healthy fats into your diet.