Meat, fish, eggs and pulses
For most people, a healthy diet means eating only moderate amounts of meat, fish and alternatives such as lentils, nuts, beans and eggs. Try to choose lower-fat versions of meat products, which means meat with the fat cut off, poultry without the skin and fish without batter, or choose pulses. Cook these foods without added fat.
Meat such as bacon and salami, and meat products such as sausages, beefburgers and pâté are all relatively high fat choices, so try to keep these to a minimum.Beans, such as tinned baked beans and pulses, are a good low-fat source of protein.
Aim to eat at least two portions of fish a week because fish are a good source of protein, vitamins and minerals, and they are low in saturated fat. You can choose from fresh, frozen or canned fish.
Oily fish are a healthy choice because they also contain omega 3 fatty acids. These include mackerel, salmon, pilchard, herring, trout, sardines and fresh tuna. Canned tuna doesn't count as an oily fish, but it is still a good source of protein and some vitamins. If you are pregnant or thinking of becoming pregnant in the next year, you should avoid eating shark, swordfish and marlin, and limit the amount of tuna you eat because of the amount of mercury in these fish.
Eggs are a rich source of protein, and contain vitamins and minerals such as vitamin D, vitamin A, vitamin B2 and iodine.
The main nutrients contained in this food group are:
• Iron
• Protein
• B vitamins, especially B12
• Zinc
• Magnesium
Fats and sugars
For most people eating atypical western diet, healthy diet means eating and drinking less of these sorts of food.
What's included?Food containing fat:
Margarine, butter, other spreading fats and low fat spreads, cooking oils, oil-based salad dressings, mayonnaise, cream, chocolate, crisps, biscuits, pastries, cakes, puddings, ice cream, rich sauces and gravies.Food and drinks containing sugar:
Soft drinks, sweets, jam and sugar, as well as foods such as cakes, puddings, biscuits, pastries and ice cream.What are the main nutrients?
As well as fat, including some essential fatty acids, foods containing fat also provide some vitamins. Some products also contain salt or sugar. Some food and drinks containing sugar also provide minerals and some provide fat.How much should I be eating?
Eat foods containing fat sparingly and look out for the low fat alternatives. Foods and drinks containing sugar should not be eaten too often as they can contribute to tooth decay.Recommendations
Cut down on food that is high in saturated fat or trans fats. Food high in saturated fat includes meat, sausages, meat pies, hard cheese, butter, cakes, pastries, biscuits and food containing coconut or palm oil.Trans fats are found in food containing hydrogenated vegetable oil such as some types of biscuits, cakes, fast food, pastry and margarine. Many manufacturers of margarines and spreads have reduced trans fats in their products to extremely low levels.
Generally people eat a lot more saturated fat than trans fats. It's important to try to eat less of both.
Choose foods that are rich in unsaturated fats instead, such as oily fish, avocados and sunflower, rapeseed and olive oils.
Remember we should also try to reduce the total amount of fat we eat, so choose low fat alternatives where available.
Have any food and drink containing sugar mainly at mealtimes to reduce your risk of tooth decay
Fruits and vegetables
Most people know that we should be eating more fruit and vegetables. But most of us aren’t eating enough. Again most people now know that we should be eating at least five portions of fruit and vegetable every day, but just what constitutes a portion and why five? We will address these specific questions at a later stage in the course, once a greater awareness of nutrition has been gained.
Fruit and vegetables are good sources of many vitamins and minerals, yet most of us don't eat enough of them. There is mounting evidence that people who eat lots of fruit and vegetables are less likely to develop chronic diseases like coronary heart disease and some cancers. These food are all on the whole also very low in fat.The recommendations are to eat a wide variety of fruit and vegetables and aim for at least five portions a day. Try to avoid adding fat or rich sauces to vegetables (such as carrots glazed with butter) or adding sugar or syrupy dressings to fruit (such as stewed apple)
You can choose from fresh, frozen, tinned, dried or juiced. Generally fresh or frozen varieties are the best choice as they are likely to be in the most natural state and contain the greatest level of nutrients. Frozen vegetables can often contain greater levels than “fresh” produce that has sat in storage for days. Dried can be a great source of fibre and energy but will not contain the same vitamin C levels.
Remember when monitoring you vegetable consumption that potatoes don't count because they're a starchy food.
Some vitamins and minerals can be easily lost when fruit and vegetables are prepared or cooked, so try to remember:
• Eat fresh fruit and vegetables as soon as possible rather than storing for a long time – or use frozen instead
• Don’t overcook. Start with boiling water and cover tightly to keep in the steam, because this speeds up the cooking. You could use a steamer or a microwave
• Use as little water as possible when you cook fruit and vegetables. If you use the cooking water for sauce or soup, you’ll recapture some of the lost vitamins and minerals
• Avoid leaving any vegetables open to the air, light or heat if they have been cut. Always cover and chill them. But don’t soak, because vitamins and minerals can dissolve away
• Don’t keep food hot for too long because vitamin levels start to drop within a few minutesThe main nutrients contained in this food group are:
• Vitamin C,
• Carotenes and other phytonutrients
• Folates
• Fibre
• Some carbohydrate
Bread and cereals
Base your meals on these sorts of foods, which should make up about a third of your diet.
Try to eat a variety and remember you can choose from all these: bread, breakfast cereals, chappattis, oats, pasta, noodles, rice, potatoes, sweet potatoes, yams, dishes made from maize millet and cornmeal, plantains, green bananas, beans and lentils. Most of us should eat more of this food group, because we eat less than the guidelines. These foods should make up a big part of our diet.People often think that starchy foods are particularly fattening. This isn't true, but starchy foods can become fattening if they're either served or cooked with fat. For example, it's the margarine or butter we spread on bread, the cream or cheese sauce we add to pasta or the oil that we use for frying that makes them fattening. So try cutting down on added fats.It is recommended that we all try to eat wholemeal, wholegrain, brown or high fibre versions where possible (e.g. brown rice, wholemeal bread). These are less processed and provide greater levels of nutrients. They also provide a slower, more We will discuss this issue in greater detail when we look at what is called the glycemic index later in the course.Try to avoid frying these foods too often (e.g. chips), adding too much fat (e.g. thickly spread butter or margarine on bread) or adding rich sauces and dressings (e.g. cream or cheese sauce on pasta)
The main nutrients in this food group are:• Carbohydrate (starch)
• Fibre
• Some calcium
• Iron
• B vitamins
Dairy foods
For a healthy diet, most people should eat dairy foods such as milk, cheese, yoghurt and fromage frais in moderate amounts. If you want to cut down on fat, choose lower fat versions whenever you can.
It is generally ecommended that you replace full fat products with lower fat versions meaning, semi-skimmed or skimmed milk, low fat (0.1%) yoghurts or fromage frais, lower fat cheeses including Edam, cottage cheese or reduced fat hard cheeses.
You can check the amount of fat by looking at the nutrition information on food labels. If you compare similar products you'll be able to choose the ones with the lower amounts of fat.
The main nutrients in this food group are:
• Calcium
• Protein
• Vitamin B12
• Vitamins A
• Vitamin D
What Nutrients Does the Body Require?
To date, fifty nutrients have been identified as essential for health. Your health can be promoted and maintained at the highest level by achieving your optimal intake of each nutrient every single day. Gradually your entire body, including your skeleton, is rebuilt and rejuvenated. Through optimum nutrition you can
• improve mental clarity and concentration
• increase IQ
• increase physical performance
• improve quality of sleep
• improve resistance to infections
• protect yourself from disease
• extend your healthy lifespanThese might sound like bold claims, yet each has been proven by proper scientific research.
The Fifty Essential Nutrients
FatsLinoleic
Linolenic
Amino AcidsLeucine
Lysine
Isoleucine
Threonine
Tryptophan
Methionine
Valine
Phenylalanine
Histidine
MineralsCalcium
Magnusium
Phosphorus
Potassium
Sodium
Sulphur
Iron
Zinc
Copper
Chromium
Selenium
Cobalt
Fluorine
Silicon
Iodine
Molybdenum
Vanadium
Arsenic
Nickel
Tin
VitaminsA (retinol)
B1 (thiamine))
B2 (riboflavin)
B3 (niacin)
B5 (pantothenic acid)
B6 (pyridoxine)
B12 (cyancobalamine)
Folic acid
Biotin
C
D
E
K
PlusCarbohydrate
Fibre
Light
Oxygen
Water
Nutrients in Food
In this section we are going to take a closer look at macronutrients, micronutrients and phytochemicals and the role they play in our diet. It is only through a greater understanding of the important part that these nutrients play in our health and body function that we can start to make an informed judgement of many fashionable diets that come and go each year. We will start by exploring the role of the macronutirents, carbohydrate, protein, fat, alcohol and water. We will then look at the often bewildering area of micronutirents, covering vitamins and minerals. Finally we will discover more about the relatively new area of phytochemicals and the functions they perform in our diet.
Macronutriets
Carbohydrates
Carbohydrates have been the subject of much argument over the last few years. There has been a spate of new fashionable diets that suggest a great reduction or even exclusion of carbohydrate form the food we eat. You will undoubtably have heard about the Atkins diet and you may well have heard the term glycemic index, all of which knock carbohydrates. So let’s take a look at these areas in more detail.
There are two main sorts of carbohydrates; sugars and starches. At present, around 60% of the carbohydrates we eat are starches and 40% are sugars. Starchy foods are plant based foods, such as cereals, bread, potatoes, pulses and rice. Vegetables also contain starch in varying amounts. Most fruits contain none, with the main exception being bananas. The carbohydrates in these foods are called polysaccharides and are known as complex carbohydrates. It is the complex carbohydrates and intrinsic sugars that should form the basis of a healthy diet.
The sugars are either intrinsic, such as those found in fruits and vegetables, which are part of the cellular structure of the food, or extrinsic, such as those found in table sugar, honey, cakes and biscuits, which are not bound into the cellular structure of the food but are “refined”, depleted of fibre or added during manufacture. Sugars include the groups called monosaccharides (glucose and fructose) and disaccharides (sucrose and lactose).
Carbohydrates are the body’s preferred source of energy and the brain especially likes it and utilises billions of glucose molecules every second. Digested carbohydrates are absorbed by the body to top up the blood glucose levels, which in turn are used to supply energy to our body cells. The body can also store small amounts of carbohydrates as glycogen in the muscles and liver. This is used as an immediate source of fuel for muscle contraction and to maintain glucose levels between meals.
Carbohydrates should comprise at least 60% of ones diet.
Fibre and gut flora
Non-starch polysaccharides and fructo-oligosaccharides are both forms of what we term fibre. Fibre is the structural element of the plants we eat and differs from sugars and starches because it resists our digestive enzymes. A form of starch known as resistant starch also resists digestion. Both fibre and resistant starch pass into the colon where they are broken down to differing degrees by the billions of bacteria that inhabit there known natural gut flora.
These help to keep us healthy by acting as a barrier against potentially harmful bacteria, helping to keep the contents of the bowels moving, digesting and fermenting resistant starches stimulating the gut’s immune system and producing certain vitamins. Some fibre go one better and help promote the growth of the beneficial gut flora such as lactobacilli which can help if the delicate balance of bacteria has been up set by diet, medication, travel, stress or illness.
The non-starch polysaccharides fibre can be split into two groups referred to as soluble and insoluble fibre. Insoluble fibre is found mainly bran based cereals, wholegrain flour, breads abd pasta. It acts like a sponge soaking up and holding onto water in the bowels to produce softer easier passing stools. A lack of this fibre leads to constipation. It can help with weight loss because it creates a feeling of fullness.
Soluble fibre is found in oats, barley, rye, fruits and pulses. It also combines with water but creates a sticky substance that slows digestion and the absorption of food into the blood stream. This helps to regulate glucose levels in our blood and makes us feel fuller for longer after food. It can also help with the management of cholesterol levels. These benefits can have important effects on you ability to loos weight.
The Glycemic Index
In 1981, professor of nutrition Dr David Jenkins was looking at how different carbohydrate-rich foods affected blood sugar levels in people with diabetes and discovered that, contrary to popular belief, many starchy foods affected blood sugar levels quite dramatically, while some sugary foods had little effect. From his research, he developed a scale called the Glycaemic Index, which quite simply ranked foods based on the effect they had on blood sugar levels.The Glycaemic Index runs from 0 to 100 and usually uses glucose or possibly white bread - which has a GI value of 100 - as the reference. The effect other foods have on blood sugar levels are then compared with this. In simple terms, the GI index tells us whether a food raises blood sugar levels dramatically, moderately or a little bit. Foods that have only a slow, small effect on blood sugar have a low GI value, while those causing a rapid and massive rise in blood sugar have a high GI value.
The theory behind diets based on the Glycaemic Index is that foods with a low GI value slowly release sugar into the blood, providing you with a steady supply of energy, leaving you feeling satisfied longer so that you're less likely to snack. In contrast, foods with a high GI value cause a rapid - but short-lived - rise in blood sugar. This leaves you lacking in energy and feeling hungry within a short time, with the result that you end up reaching for a snack. If this pattern is frequently repeated, you're likely to gain weight as a result of constantly overeating.
There are many books and websites that list the GI index for different foods. Food values may vary slightly depending on the source, but in general, they should all be roughly the same.Many lists divide the foods into low, medium/moderate and high categories. Foods in the low category usually have a GI value of 55 or less; in the medium category, a GI value of 56 to 69; and in the high category, a GI of 70 or more. You might be surprised by some of the foods included in the low and high categories - for example, 'healthy' rice cakes and branflakes actually have a high GI whereas salted peanuts and milk chocolate have a low GI value!
