Food is any substance humans, animals or plants eat/take in for energy, growth and life maintenance. Examples of food include yam, garri, semolina, banana, apples, meat and fish.
On the other hand, nutrients are components of food; that means food contains nutrients. There are seven nutrients (carbohydrates, protein, lipids (fats and oils), water, minerals, vitamins and phytochemicals) but a particular food may not contain all the nutrients hence we are advised to take a mixture of foods so as to get all the nutrients.
The seven nutrients referred to above are split into two groups: Macronutrients (carbohydrates, protein, lipids [fats and oils] and water) and Micronutrients (vitamins, minerals and phytochemicals)
Once food is eaten by man, the nutrients contained in it undergo different processes of digestion and absorption in the body.
Lipids are organic compounds that do not dissolve in water but do so in organic solvents such as chloroform and ether. At room temperature; when in solid form, lipids are called fats but in liquid form they are called oils.
There are three nutritionally important classes of lipids:-Triglyceride, Phospholipids and Sterols.
Cholesterol is a sterol.
The simplest form of lipids is fatty acid; also lipids can be saturated or unsaturated;
Unsaturated fat is either monounsaturated or poly unsaturated. Daily fat intake should not exceed 35 percent of total daily calorie requirement which is about 2000Kcals; of this 35 percent, saturated fat should contribute only 11 percent (unsaturated fat-24 percent, saturated fat—11 percent).
One gram of every type of lipid (fat and oil) gives about 9Kcals of energy; in Britain the daily recommended total lipid consumption is 95 grams for men and 70 grams for women; of this, maximum saturated fat is 30 grams for men and 20 grams for women.
Every food contains saturated and unsaturated fat; in general animal food contains more saturated fat than unsaturated fat while plant food contains more unsaturated fat than saturated fat. Unsaturated fats are liquid at room temperature.
Functions of lipids include provision of energy, holds body organs and nerves in position, maintenance of body temperature, palatability of food, absorption and transportation of some vitamins and formation of hormones among others.
So we must eat food containing fat and below are some sources of healthy fat:
1. Oily Fish
Fish is a major source of high quality fat in our diet. Though there may be no scientific basis for this; persons who live along the river side tend to have healthier weight than those upland and to an extent, healthier skin. Like I said it may just be an observation that has not been subjected to scientific challenge.
Oily fish has a lot of nutrients such as omega-3 fatty acids, protein, vitamins (D and B2) and minerals such as calcium, phosphorus and potassium.
Oily fish includes sardines, salmon, kote, icefish, tuna, mackerel and trout.
2. Nuts and Nut Butter
Nuts contain a lot omega-3fatty acid which is very good for the heart; they also contain other nutrients which are essential for our health.
The nuts include walnuts, peanuts, almonds, cashew nuts and pistachious.
3. Whole egg
Whole eggs are rich in protein, fat and micronutrients. The egg has two parts; the white part and the yolk (yellow part). The white is very rich in protein while the yellow part called the yolk is very rich in cholesterol; the latter (cholesterol) is worsened by frying the egg, as some cooking oils also contain cholesterol.
However, eggs contain all nine essential amino acids in the required quantities besides minerals and vitamins.
In adults about two eggs a week will do but as we age this should reduce.
4. Avocado pear
Avocado pear is very rich in monounsaturated fat. The average avocado contains about 30 grams of fat and as such moderation is still key; it could be used as bread spread instead of butter.
Studies reveal that avocado lowers cholesterol level, the pear contains monounsaturated fat which is said to lower Low Density Lipid (LDL) cholesterol in the blood, this is the bad cholesterol while it raises the level of High Density Lipid (HDL) cholesterol which is the good cholesterol. Bad Cholesterol is associated with narrowing of blood vessels which can lead to stroke, heart disease.
5. Vegetable oils
Vegetable oils are rich in unsaturated fat; both monounsaturated and polyunsaturated and are therefore sources of healthy fat. Examples include rapeseed oils, soya bean oils, sunflower oils, sesame oils and olive oils. They also contain omega-3 fatty acid which is very good for the heart.
Olive oils can be used for salads and like the others in frying food. However, each table spoon is packed with about 100 Kcals, moderation is also key.
6. Dark chocolate
Dark chocolate with at least 70 percent of cocoa is very good for the heart. It is a very rich source of fat (contributing 65 percent of the total available calorie in chocolate), antioxidants, fibre, and minerals such as iron, manganese, copper and magnesium.
Studies have shown that those who eat dark chocolate daily are less likely to die from heart disease by half.