This is due to an allergy to the food. Different foods react differently in different people. What is food for some may be poison for others. You've probably heard the expression , one man s meat is another man s poison. So, it is very important to clear the allergy to the nutrients.
Allergic people can tolerate food that is low in nutrition better than nutritious food.
But upon clearing the allergy, you should try to eat more wholesome, nutritious foods. You should avoid refined, bleached food that is devoid of nutrients. Many people who are feeling poorly due to undiagnosed food allergies, may take vitamins or other supplements to increase their vitality after they get treated for the specific supplements. If they happen to be allergic to the nutritional supplements they are taking, this can actually make them feel worse. Only after clearing those allergies, can their bodies properly assimilate them.