Nutritional disease, any of the nutrient-related diseases and conditions that cause illness in humans. 
They may include deficiencies or excesses in the diet, obesity and eating disorders, and chronic diseases such as cardiovascular  disease,  hypertension, cancer, and diabetes mellitus. 
Nutritional diseases also include developmental abnormalities that can be prevented  by diet, hereditary  metabolic disorders that respond to dietary treatment .
For Diabetes reversal and prevention  natural  vitamin and minerals are very important .
Glycemic Index and Diabetes
The glycemic index, or GI, measures how a carbohydrate-containing food raises blood glucose. Foods are ranked based on how they compare to a reference food — either glucose or white bread.
A food with a high GI raises blood glucose more than a food with a medium or low GI.
Meal planning with the GI involves choosing foods that have a low or medium GI. If eating a food with a high GI, you can combine it with low GI foods to help balance the meal.

Ex : Polished Rice have High GI and Brown rice  has Low GI. Meats and fats don’t have a GI because they do not contain carbohydrate. 
Fruits & Veg have both   low & High GI . So select your food based on GI   .
The amount of each nutrient you should consume depends on your age. 
According to National Institute of Nutrition (NIN), consuming a diet balanced in all essential food groups, micro and macronutrients will stave off risk of developing diabetes and a range of other non-communicable, lifestyle diseases. NIN suggests loading up on phytonutrients, dietary fibre, antioxidants "for delaying ageing and preventing the processes which lead to diseases like diabetes, cancer and heart ailment," as mentioned in Dietary Guidelines for Indian, A Manual released by NIN.
Undeniably, individuals with excessive weight are at a greater risk of falling prey to lifestyle diseases such as diabetes. Therefore, besides eating healthy, regular physical activity is of the utmost importance to beat obesity and avoid risk of developing lifestyle diseases including diabetes.
Nutritional Deficiencies (Malnutrition)
What are nutritional deficiencies?
The body requires many different vitamins and minerals that are crucial for both body development and preventing disease. These vitamins and minerals are often referred to as micronutrients. They aren’t produced naturally in the body, so you have to get them from your diet.
A nutritional deficiency occurs when the body doesn’t absorb or get from food the necessary amount of a nutrient. Deficiencies can lead to a variety of health problems. These can include digestion problems, skin disorders, stunted or defective bone growth, and even dementia.
Types of nutritional deficiency
It’s possible to be deficient in any of the nutrients your body needs. Some common types of nutritional deficiencies include:

Iron deficiency
The most widespread nutritional deficiency worldwide is iron deficiency. Iron deficiency can lead to anemia, a blood disorder that causes fatigue, weakness, and a variety of other symptoms.
Iron is found in foods such as dark leafy greens, red meat, and egg yolks. It helps your body make red blood cells. When you’re iron-deficient, your body produces fewer red blood cells. The red blood cells it produces are smaller and paler than healthy blood cells. They’re also less efficient at delivering oxygen to your tissues and organs.
According to the World Health Organization (WHO), over 30 percent of the world’s population has this condition. In fact, it’s the only nutritional deficiency that’s prevalent in both developing and industrialized countries. Iron-deficiency anemia affects so many people that it’s now widely recognized as a public health epidemic.

Vitamin A deficiency

Vitamin A is a group of nutrients crucial for eye health and functioning and reproductive health in men and women. more