Cameroon GCE O-Level Food and Nutrition cheat sheet

Six nutrient classes: carbohydrates, proteins, fats, vitamins, minerals, water. Carbohydrates and fats are the main energy-yielding nutrients (4, 4 and 9 kcal per gram respectively); vitamins, minerals and water yield no energy.

Macronutrient roles: carbohydrates supply glucose and dietary fibre; proteins supply amino acids for growth, repair and enzymes; fats supply essential fatty acids, carry fat-soluble vitamins and give concentrated energy.

Fat-soluble vitamins A, D, E and K are stored in the liver and adipose tissue and need dietary fat for absorption; water-soluble vitamins B-complex and C are not stored in quantity and excess is excreted in urine.

Key mineral functions: calcium and phosphorus for bone and teeth, iron for haemoglobin (deficiency causes anaemia), iodine for thyroid hormones, sodium and potassium for fluid balance.

Digestion sequence: mouth (salivary amylase begins starch breakdown) → stomach (acid and pepsin begin protein breakdown) → small intestine (main site of digestion and absorption, via villi) → large intestine (water and mineral absorption) → rectum/anus.

Bile from the liver, stored in the gall bladder, emulsifies fats in the small intestine; pancreatic amylase, lipase and protease complete digestion; digested nutrients are absorbed into blood or lymph.

Metabolism: absorbed glucose is used for energy, stored as glycogen in liver and muscle, or converted to fat; excess amino acids are deaminated in the liver and nitrogen excreted as urea.

Basal metabolic rate rises with body size, muscle mass, growth, fever and pregnancy, and falls with age; energy needs equal BMR plus activity allowance plus thermic effect of food.

Energy balance rule: intake greater than output leads to weight gain; intake less than output leads to weight loss; 1 kg body fat is roughly equivalent to 7,700 kcal (about 32,000 kJ).

A balanced meal combines a starchy staple, a protein food, vegetables/fruit and a fat source; a balanced diet supplies all nutrients in the correct proportions and adequate energy.

Meal-planning decision rules: consider nutritional needs of each family member, food available and in season, budget, cooking time, equipment, and variety of colour, texture and flavour.

Dietary guidelines: eat a variety of foods, increase fibre and vegetables/fruit, limit refined sugar, salt and saturated fat, drink adequate safe water, and maintain healthy body weight through activity.

Infants: exclusive breastfeeding for the first six months, then complementary foods from six months while breastfeeding continues; weaning foods should be soft, energy-dense and hygienically prepared.

Children and adolescents need proportionally more protein, calcium and iron for growth; iron needs rise at adolescence, especially for girls due to menstruation.

Pregnancy and lactation raise needs for protein, iron, folate, calcium and energy; undernutrition in pregnancy raises risk of low birth weight.

Elderly people need energy-dense, nutrient-rich, easily chewed foods, more calcium and vitamin D for bone health, and adequate fluid; fibre and water help prevent constipation.

Illness and convalescence increase protein and energy needs; fever increases fluid needs; some conditions (e.g. diabetes) require controlled carbohydrate and sugar intake.

Special diets: vegetarians must combine plant proteins (e.g. legumes with cereals) to obtain all essential amino acids; lactose intolerance requires non-dairy calcium sources.

Purchasing rules: buy from clean, licensed sellers, check expiry dates and packaging integrity, prefer seasonal and local produce, compare unit price (price ÷ quantity) to judge value, and buy perishables last.

Storage zones: dry store (cool, dark, ventilated, off the floor), refrigerator (0–5 °C, raw foods below cooked foods), freezer (−18 °C or below); never refreeze thawed food.

Preservation methods work by removing or controlling moisture, temperature, oxygen or micro-organisms: drying, salting, smoking, pickling, sugaring, canning, freezing, irradiation and fermentation.

High-risk foods (meat, fish, eggs, milk, cooked rice, soups) support rapid bacterial growth between 5 °C and 60 °C - the danger zone; keep hot food above 60 °C and cold food below 5 °C.

Cross-contamination is prevented by separate chopping boards for raw meat and ready-to-eat food, washing hands and utensils, and covering food.

Personal hygiene for food handlers: short clean nails, clean hands, hair covered, no coughing or sneezing over food, no handling food when ill with diarrhoea, and clean aprons.

Kitchen hygiene: wash surfaces and cloths frequently, keep refuse covered and away from food, control pests, and use safe water; boil or treat water where supply is unsafe.

Food spoilage signs: off-odours, slime, mould, discolouration, gas in cans; bulging cans and foul-smelling food must be discarded, not tasted.

Cooking methods divide into moist (boiling, steaming, stewing, poaching), dry (baking, roasting, grilling, frying) and combination (braising); moist methods are gentler on nutrients, dry methods add flavour and browning.

Heat transfer is by conduction (direct contact, e.g. pan), convection (moving hot air or liquid, e.g. oven, boiling water) and radiation (grill, microwave).

Effects of heat: proteins coagulate (egg sets, meat firms), starch gelatinises and thickens liquids, sugars caramelise and brown, fats melt and can burn, vitamins (especially C and B) are partly destroyed.

Leavening agents: yeast (fermentation produces carbon dioxide), baking powder and bicarbonate of soda (chemical), and air or steam (physical) make mixtures rise.

Roux is equal weights of fat and flour cooked together, then liquid added, to thicken sauces; cornflour and arrowroot are starch thickeners that need cold water mixing first.

Nutrient retention rules: prepare vegetables just before cooking, use minimal water, cook quickly, keep skins where possible, avoid prolonged soaking, and use cooking liquid in soups or stews.

Equipment selection: match pan size to hob, use lids to conserve heat and fuel, use a food thermometer for meat doneness, and keep knives sharp for safety and efficiency.

Safety rules: turn pan handles inward, keep flammable materials away from heat, lift lids away from the face, and never leave hot oil unattended.

Consumer rights include safety, accurate information, choice, redress and being heard; responsibilities include reading labels, keeping receipts and complaining properly.

Food labels must be read for ingredients list (in descending order of weight), net weight, expiry/best-before date, storage instructions, and nutritional information.

Unit pricing (price ÷ weight or volume) allows comparison of value between different package sizes and brands; buying in bulk is cheaper only if the food can be stored without waste.

Budgeting rule: record income, fixed expenses and variable expenses; food spending should be planned and controlled; a shopping list reduces impulse buying.

Resource management: plan menus, make a shopping list, compare prices, use leftovers creatively, buy seasonal produce, and reduce waste to save money and resources.

Food fraud and misleading claims: beware of false health claims, fake expiry dates, adulterated products; report unsafe food to health authorities.

Income-generating and home-production options: kitchen gardens, small livestock, food processing (e.g. drying, juicing) and group buying can lower food costs.

Food poisoning causes: bacteria (Salmonella, Staphylococcus, Clostridium), viruses, moulds, chemicals and poisonous plants; symptoms include vomiting, diarrhoea, abdominal pain and fever.

First aid for food poisoning: give plenty of fluids (oral rehydration solution), rest, avoid solid food until vomiting stops, and seek medical help if symptoms are severe or prolonged.

Choking first aid: encourage coughing; if unable, give up to five back blows between shoulder blades, then abdominal thrusts (Heimlich manoeuvre); call for help.

Burns and scalds: cool under running water for at least 10–20 minutes, do not apply oil or toothpaste, cover with clean non-stick dressing, seek help for large or deep burns.

Cuts: clean with safe water, apply pressure to stop bleeding, cover with sterile dressing; seek medical help for deep or dirty wounds.

Community health measures: safe water supply, sanitation, food hygiene education, immunisation, growth monitoring, and control of disease vectors.

Malnutrition types: protein-energy malnutrition (marasmus and kwashiorkor), micronutrient deficiencies (iron, vitamin A, iodine); prevention through balanced diets, breastfeeding and food fortification.

Work sequence: read the recipe, gather ingredients and equipment, wash hands and prepare surfaces, prepare ingredients, cook, then clean as you go.

Weighing and measuring accuracy: use dry measuring cups for dry ingredients, liquid measures at eye level, and level off with a straight edge for accuracy.

Presentation principles: balance colour, texture and shape; keep portions neat; use clean plates; garnish with edible, fresh items; avoid overcrowding the plate.

Table setting: cutlery arranged in order of use from outside in, fork left, knife and spoon right, glass above the knife, napkin left of the fork.

Service styles: plate service, family/table service, buffet and self-service; choose according to number of guests, formality and available equipment.

Hygiene in practical work: tie hair back, wear clean apron, wash hands before handling food, keep raw and cooked foods separate, and wash up in hot soapy water.

Evaluation of practical work: judge appearance, texture, flavour, nutritional value, cost, time and hygiene; note improvements for next time.

Staple foods: cassava (fufu, garri, water fufu), maize (corn fufu, pap), plantain, cocoyam, yams, rice, millet and sorghum; these supply energy mainly as carbohydrate.

Protein sources: beans, groundnuts, egusi, soya, fish, poultry, beef, goat, pork and insects; legumes are cheaper plant protein and are often combined with cereals.

Local vegetables and fruits: huckleberry (eru), okra, bitterleaf, cassava leaves (ntumba), pumpkin leaves, tomatoes, pepper, mango, pawpaw, guava, banana and citrus; they supply vitamins, minerals and fibre.

Palm oil, groundnut oil, coconut and egusi supply fats; palm oil is rich in vitamin A precursors (carotenoids).

Traditional dishes: ndolé, eru, achu soup, koki (steamed bean pudding), ekwang, pepper soup, jollof rice, puff-puff, beignets and plantain chips; many combine staple, legume and vegetable for balance.

Food culture: meals are often shared from a common dish; hospitality, ceremonies and festivals feature specific foods; preservation by drying, smoking and fermenting (e.g. cassava fermentation) is traditional.

Sustainability: support local and seasonal foods, reduce food waste, use kitchen gardens and agroforestry, protect water sources, and avoid overfishing and bush burning.