4.6 Classes of Foods Based on Composition

Carbohydrate, fat, protein and fibre are components of foods and not the foods themselves. In beginning to study nutrition, many people make the mistake of getting nutrients mixed up in their minds with the foods themselves. Avoid this error. “Meat is a protein”, some people say. However, meat is a substance in which protein is a significant component but its other major component is fat.

Remember that this is true of all natural foods. Natural foods are all organisms or parts of organisms, and these biological substances are never made up from one component only. Bearing that in mind; foods eaten primarily for carbohydrate are, for example, bread, flour-goods, cereals, rice, corn and potatoes. Note that these all contain some protein, at least a trace of fat and variable amounts of fibre.

The same comment does not necessarily apply to foods that have been subject to food processed including separation and refining, such as sugar or potato starch. These may be almost pure carbohydrate, other components having been separated away, often to the detriment of human health for those that may rely too heavily on processed foods.

Few natural foods consist overwhelmingly of fat, but may have a very high proportion. Nuts (except chestnuts) contain more fat than other nutrients, as do avocados. There are very significant amounts of fat in beans, seeds, and in meats, and fatty fishes, along with the substantial protein contribution. Fats, like carbohydrates, become the overwhelming component when they have been purified, or separated out, as in dripping, lard, vegetable oils, butter and cream.  Plant oils that have been separated from seeds contain nearly pure fat.

There are few foods in which protein is dominant, most commonly being accompanied by significant amounts of fat. Meat, fish, eggs and dairy products all contain a great deal as do plants sources like plant seeds and some beans. Only highly processed foods contain overwhelmingly protein, like texturized vegetable protein (TVP), a type of soya protein isolate, in which soya protein has been artificially separated from its fat content and presented as a protein concentrate product. Milk is a rather balanced mixture of protein fat and carbohydrate.

Plant fibre is high in fresh vegetables and fruits, and also in the outer bran coat of wheat, rice and oats. It makes no direct nutritional contribution, but it does positively support the processes of digestion, in the correct quantities, and contributes to function of the colonic bacteria and accordingly to the health and function of the digestive tract and other organs.

In Module 9 we will delve deeper in to the composition of different food groups so that you will fully understand the power of combining different foods according to their micro- and macro-nutrient content. With this complete knowledge of food gained through this nutrihub foundation course, you will understand how to manipulate nutrient levels in the diet to support cellular detoxification. This is a truly powerful and unique approach to optimising long-term health.

Macronutrient Intake Guidelines

Different people have different requirements of daily macronutrient intake due to many factors such as age, activity and gender. There are some government guidelines for adults suggesting the following levels on a daily basis:

Table 4.1 Food Standards Agency (FSA) macronutrient guidelines for the UK adult daily diet

The evidence for nutritional recommendations comes from a range of sources but particular emphasis is placed on COMA (Committee on Medical Aspects) reports:

• 1991; COMA report on energy and nutrients provided evidence for the dietary recommendations for total fat, saturated fat, total carbohydrate, sugars, and dietary fibre.
• 1994; COMA recommended reducing the average salt intake of the population to 6g a day based on evidence of a link between high salt intake and high blood pressure. In 2003, the SACN (Scientific Advisory Committee on Nutrition) reviewed the evidence (e.g. Intersalt study and Dietary Approaches to Stop Hypertension (DASH) sodium trial) since 1994 and concluded the strength for the association between high salt intake and hypertension had increased. High blood pressure increases the risk of stroke and cardiovascular disease. SACN confirmed that reducing salt intake to 6g per day would benefit the whole population.

However, as you will go onto learn in subsequent modules, there are many different factors you have to consider when designing diets. Government guidelines, certainly in the case of vitamins and minerals, do not take into account individual nutrient status and requirements. A “one size fits all”adopting Dietary Reference Values (DRVs), Recommended Daily Allowances (RDAs) or Reference Nutrient Intakes (RNIs) when devising a nutrition programme will hardly ever benefit the needs of the individual, as these numbers are taken from data looking at the general population (described in more detail in Module 6). What one person requires from their diet is very different to what you require. That is the beauty of this systems-orientated nutrition approach we subscribe to at nutrihub; you are helping support the health requirements of an individual. We will explore this in more detail throughout the rest of this course.