Can you give an example of such a nutrient? I think a reduced intake diet without excluding large categories of food is very unlikely to result in nutrient defi

Can you give an example of such a nutrient? I think a reduced intake diet without excluding large categories of food is very unlikely to result in nutrient deficiency. We are surrounded by food that has very high nutritional value. A steak or a piece of salmon or contemporary vegetarian/vegan equivalents are all calorie and micronutrient parties. Most of human evolution took place with much more limited access to nutrition.