Diet has always played a vital role in supporting health.

The body can derive all the energy, structural materials and regulating agents that it needs from the foods we eat.  Water, Carbohydrates, Lipids, Proteins, Vitamins and some of the minerals found in foods are nutrients – substances the body uses for the growth, maintenance and repair of its tissues.  Other nutritionally important constituents of foods are the fibres – members of the carbohydrate family that also support good health.

In the body, three of the organic nutrients can be used to provide energy: Carbohydrate, fat and protein.  In contrast, vitamins, minerals and water do not yield energy in the human body.

Energy Measured in kilocalories: The energy released from carbohydrates, fats and proteins can be measured in calories  - To ease calculations, energy is expressed in 1000 calorie units known as kilocalories.

The amount of energy a food provides depends on how much carbohydrate, fat and protein it contains.  When completely broken down in the body, a gram of carbohydrate yields about 4 kilocalories of energy; a gram of protein also yields 4 kcalories and a gram of fat yields 9 kcalories.

The body uses the energy-yielding nutrients to fuel its metabolic and physical activities.  The energy from foods supports every activity from quiet thought to vigorous sports.

If the body does not use these nutrients to fuel metabolic and physical activities, it rearranges them into storage compounds, to be used between meals and overnight when fresh energy supplies run low.  If more energy is consumed than expended, the result is weight gain.  Similarly, if less energy is consumed than expended, the result is weight loss.

We shall provide you articles from time to time, which will speak about the role of diet in different conditions.

• Dietary Fibres
• Understanding the role of diet
• Generalizability of dietary patterns

Dietary Fibers: current trends and health benefits in the metabolic syndrome and type 2 diabetes

Dietary fiber may contribute to both the prevention and treatment of type 2 diabetes mellitus (T2DM). In epidemiological studies the intake of insoluble fiber, but not the intake of soluble fiber, has been inversely associated with the incidence of T2DM. In contrast, in postprandial studies, meals containing sufficiently quantities of beta-glucan, psyllium, or guar gum have decreased insulin and glucose responses in both healthy individuals and patients with T2DM. Diets enriched sufficiently in soluble fiber may also improve overall glycemic control in T2DM. Insoluble fiber has little effect on postprandial insulin and glucose responses. Fiber increases satiety. In some studies, insoluble fiber has been associated with less weight gain over time. Limited cross-sectional evidence suggests an inverse relationship between intake of cereal fiber and whole-grains and the prevalence of the metabolic syndrome. Although long-term data from trials focusing on specifically dietary fiber are lacking, meeting current recommendations for a minimum fiber intake of 25 g/d based on a diet rich in whole grains, fruits and legumes will probably decrease the risk of obesity, the metabolic syndrome and T2DM.

Understanding the role of diet in type 2 diabetes prevention.

The number of people with type 2 diabetes is increasing at an alarming rate. Almost 4% of the UK population currently have diagnosed diabetes. Non-modifiable risk factors for diabetes include genetic predisposition, some black and ethnic minority groups and increasing age. Type 2 diabetes, (formally known as maturity onset diabetes), used to be a condition affecting adults only, although due to the increasing levels of obesity, it is now being diagnosed in young people and children. A healthy diet and lifestyle can help to prevent or delay the development of type 2 diabetes. In particular, strategies to reduce obesity will have a beneficial effect on the prevalence of type 2 diabetes, as excess adiposity (particularly central adiposity) is a strong risk factor for the condition. Dietary measures to reduce the risk of coronary heart disease will also help prevent diabetes. Diets low in fat (particularly saturated fat), and high in fibre and complex carbohydrates are effective in reducing the risk of developing diabetes. Good quality evidence from trials is required to determine the role of specific micronutrients in diabetes prevention.

Generalizability of dietary patterns associated with incidence of type 2 diabetes mellitus.

Jean Mayer US Department of Agriculture, Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.

BACKGROUND: Reduced rank regression (RRR) has been used to derive dietary pattern scores that predict linear combinations of disease biomarkers. The generalizability of these patterns to independent populations remains unknown. OBJECTIVE: The goal was to examine the generalizability of dietary patterns from the following prior studies using RRR to predict type 2 diabetes mellitus (T2DM): the Nurses' Health Study (NHS), European Prospective Investigation into Cancer and Nutrition Germany (EPIC), and Whitehall II Study (WS). DESIGN: The relative weights of food groups of each dietary pattern were used to generate each dietary pattern score in the Framingham Offspring Study (n = 2879). Each of the external scores (confirmatory scores) was examined to determine whether it could predict incident T2DM during 7 y of follow-up as well as scores developed internally in the Framingham Offspring Study using a Cox-proportional hazard model adjusted for T2DM risk factors. RESULTS: Intakes of meat products, refined grains, and soft drinks (caloric and noncaloric) were found to be common predictive components of all confirmatory scores, but fried foods, eggs, and alcoholic beverages were predictive in some, but not in all, confirmatory scores. On the basis of a continuous increase in the score by 1 SD, the NHS-based confirmatory score predicted T2DM risk (hazard ratio: 1.44; 95% CI: 1.25, 1.66). However, T2DM risk was only weakly predicted by the EPIC-based score (hazard ratio: 1.14; 95% CI: 0.99, 1.32) and the WS-based score (hazard ratio: 1.16; 95% CI: 1.00, 1.35). CONCLUSIONS: The study suggested that dietary patterns that predict T2DM risk in different populations may not be generalizable to different populations. Additional dietary pattern studies should be conducted with regard to generalizability.