Heartsavers - Diet
It is unlikely that you will be short of protein
even in a low fat diet, protein abounds in vegetables and cereals.
Prevention of coronary heart disease.
The role of protein in the diet
Proteins are large molecules which are made from a connection between smaller molecules called amino acids. The connections in the protein molecules are different for each animal and plant species, so when you eat protein your digestive system breaks down the protein into it's component amino acids and re-assembles them in the body into human protein. These proteins are then used by the body to make new tissues. Amino acids are also used in the body to produce various hormones.
Plants can make all the protein they need from the basic elements found in the soil and atmosphere such as nitrogen, carbon and water. Humans and animals, however, cannot and so we need a regular food source.
It is often assumed that the role of protein in the diet is not very significant with regard to heart disease, but this is not the case.
Different types of protein have different effects on cholesterol and fat levels in the bloodstream. For example if you ate a meal consisting of soya protein, the hormonal activities responsible for blood cholesterol levels would be less extreme than if you ate a meal with milk as the source of protein. This suggests that milk protein would lead to higher blood cholesterol levels which is a major risk factor in heart disease.
Protein Quality
It has often been stated that protein from animal sources such as meat, eggs, milk, etc. are the best quality proteins and that vegetable sources are of inferior quality. It has further been suggested that if you get most (or all) of your protein from plant sources you should "combine" your protein food at each meal to ensure you get enough of the different types of amino acids. This advice is now outdated and it is now accepted by most nutritionists that you will get an adequate protein intake from purely plant sources without paying particular attention to combining.
Protein Requirements
Experts are still not entirely sure about how much protein we need and the recommended figure has been changed several times over the years.
The best consensus appears to be that around 9% - 10% of your daily energy requirements should be met by protein. That's around 60 grams per day for an adult male and around 50 grams per day for an adult female. Obviously children will need proportionately less protein. The average consumption of protein in the UK exceeds this figure by a factor of approximately 50%.
There are certain health risks associated with a high protein intake; kidney function can be affected and the calcium balance can be affected leading to mineral loss from the bones and osteoporosis.
Food Sources
Pulses: peas, bean, lentils, soya products. Grains: wheat, oats, rice, pasta, bread. Nuts: peanuts, brazil, almonds. Seeds: pumpkin, sunflower. Meat and dairy products.
Of the above the best by far is soya protein particularly if you want to reduce your intake of animal products to reduce fat consumption.