Adolescence is a critical period of growth and development, so good nutrition is essential. The body demands more calories and nutrients during early adolescence than at any other time of life. Calories are the measurement used to express the energy delivered by food. On average, boys require about 2,800 calories per day; and girls, 2,200 calories per day. If they are active in sports, their requirements are even higher.

Nutrients and Energy

The nutrients protein, carbohydrates, and fats in food serve as the body’s energy sources. Each gram of protein and carbohydrate supplies four calories, or units of energy, whereas fat contributes more than twice as much: nine calories per gram.

Protein

Protein is an important nutrient needed for the growth and repair of cells. 50% percent of body weight is made up of protein. Protein can also be used for energy, especially if not enough carbohydrate foods are eaten. Protein needs are increased during times of cell growth and repair such as during childhood and adolescence.

Protein can come from animal or plant foods such as:

• Meat, chicken, fish
• Eggs
• Nuts and seeds
• Dried beans and lentils
• Dairy products such as milk, yogurt and cheese

Too Much Protein

Some people use protein supplements in an effort to build muscle. The best way to build muscle is to do exercise that uses muscle strength. Although muscle is made of protein, the preferred fuel for working muscles is carbohydrate.

It can be dangerous and harmful to adolescents, children and adults to follow diets high in protein or protein shakes and low in other nutrients. It can damage the kidneys and create a serious impact on their health. It is important that diet is well balanced and provides all nutrients essential for good health.

Carbohydrates

Carbohydrate is an important nutrient found in many foods. Carbohydrate is an important source of energy for the body. They are divided into complex and simple carbohydrates. Many complex carbohydrate-containing foods are high in dietary fiber and are healthy food choices. Complex carbohydrate-containing foods provide the body with energy throughout the day.

The rate at which carbohydrate-containing foods are digested varies greatly. Complex carbohydrate-containing foods are digested slowly and therefore provide a longer-lasting release of energy with a low glycaemic index (GI). It is often labeled on the food that we buy in the supermarket.

Simplex carbohydrates such as sweets, cakes, candies, chocolate, cupcakes, desserts etc provide high surge of blood sugar, fast and short release of energy with high GI index and their consumption leads to obesity and diabetes.

Low GI foods include wholegrain bread, pasta, oats, apples, banana, apricots and oranges, yogurt and milk, dried beans and lentils.

High GI foods include white bread, processed cereals, short-grain rice, potato, most cracker biscuits, watermelon.

Complex carbohydrate foods like breads and cereals are also fuel to the probiotic (healthy and beneficial) bacteria in our gut and which are essential for a healthy digestive tract. For good health, eat a variety of low GI, high fibre complex carbohydrate-containing foods each day.

Examples include:

Fresh, canned or dried fruits

Rice (preferably brown), bread (wholemeal), quinoa (also rich in protein), noodles and pasta (preferably brown/whole grain varieties)

• Low-fat milk and yogurt
• Whole grain breakfast cereals
• Legumes such as beans, chickpeas and lentils
• Starchy vegetables such as potato, sweet potato, carrots, corn

Fats

Fat is an essential part of our diet and is important for good health. There are different types of fats, with some fats being healthier than others. It is important to eat healthy fats in moderation as part of a balanced diet.

Unsaturated fats

Unsaturated fats are healthy fats and are an important part of a healthy diet. These fats help reduce the risk of heart disease and lower cholesterol levels.

Polyunsaturated fats:

• Omega-3 fats which are found in oily fish such as salmon, sardines and anchovies, walnuts, canola oil, soy, chia seeds, flaxseeds
• Omega-6 fats which are found in safflower and soybean oil, some nuts, including brazil nuts.

Monounsaturated fats:

• Found in olive and canola oil, avocados and some nuts, such as cashews and almonds.

Saturated fats

Saturated fats are unhealthy fats, which may increase the risk of heart disease and high cholesterol levels. These fats are solid at room temperature and are found in:

Animal-based products:

• Dairy foods – such as butter, cream, ice-cream
• Meat – such as fatty cuts of beef, pork and lamb, processed meats like salami, and chicken skin

Some plant-derived products:

• Palm oil
• Coconut oil
• Cooking margarine

Saturated fats are also commonly found in many processed food::

• Fatty snack foods
• Deep-fried take away foods e.g. french fries, chicken nuggets, spring rolls, battered/crumbed fish
• Packaged cakes and biscuits
• Pastries and pies.

Vitamins

Vitamins are important building blocks in our diet. They are vitally important for function of different organs (vitamin A for eyes and vision), enzymes (vitamin B) and neuronal cells (vitamin B12 and folic acid), production of blood cells (iron, vitamin B12 and folic acid), wound healing (vitamin C), bones and teeth (calcium and vitamin D), for production of blood clotting factors (vitamin K) etc.

Diet for children growing adolescents is very important to be rich in vitamins and minerals. Vitamins are divided into oil-soluble vitamins (A, D, E, K) and the rest are water-soluble vitamins.

Best sources of vitamins

• Vitamin A: Dairy products, eggs, liver, fish, fortified cereals, darkly colored fruits, and leafy vegetables
• B1 (Thiamin): Whole grains, pork, beans, seafood
• B2 (Riboflavin): Milk, whole grains, dairy, beef, lamb, eggs, green leafy vegetables
• B3 (Niacin): Meat, fish, wholemeal breads and cereals, beans, peas, nuts
• B6 (Pyridoxine): Fish, poultry, lean meat, whole grains, potatoes
• B9 (Folate): Dried beans, green leafy vegetables, oranges, beans, poultry, fortified cereals, nuts
• B12 (Cobalamin): Fish, red meat, poultry, dairy products, eggs
• Pantothenic acid: Sunflower seeds, mushrooms, peanuts, yeast, yogurt
• Biotin: Peanut butter, hard-boiled eggs, wheat germ
• Vitamin C: Berries, kiwi, bell peppers, tomatoes, melons, citrus fruits, oranges
• Vitamin D: Egg yolk, fatty fish, and milk. Also made by the skin when exposed to sunlight
• Vitamin E: Vegetable oils, nuts, dark green vegetables, avocados, and whole grains

Minerals

• Calcium: Dairy products (milk, yogurt, cheese, etc.), calcium-fortified juice, or soy milk
• Iron: Red meat, pork, fish, chicken, beans, soy foods, green veggies, and raisins
• Magnesium: Whole grains, whole-grain breads, nuts and seeds, potatoes, milk, and bananas
• Phosphorus: Dairy products, meat, and fish
• Potassium: Banana, dry fruits, beans, broccoli, potatoes (with skins), citrus fruits, peas, and other legumes
• Zinc: Red meat, chicken, seafood, soy foods, dairy products, whole grains, nuts
• Sodium: Usually used as a food additive or kitchen salt. Many processed food contain high amount of salt (NaCl). It's recommended that we eat less than 2,300 mg of sodium a day because it will lead to high blood pressure and water retention and headache.

Water

Adequate intake of fluids during the adolescent years is important because it supports many body functions. Fluid requirements depend on size, age, and level of physical activity. Male adolescents should get 2.4 to 3.3 liters of water per day and female adolescents need at least 2.1 to 2.3 liters per day.

Water and other fluids keep tissues moist, regulates body temperature, lubricates joints, prevents constipation, supports kidneys and liver function and make nutrients available to the body. Dehydration can occur if an adolescent doesn't get enough fluids throughout the day and may result in kidney problems, developing kidney stones, skin conditions, including acne, allergy and asthma, fatigue, headaches, weight gain, and diabetes.

Not all fluids are suitable for hydration. Water is the best way to keep hydration. Many foods are high in water content and contribute to an overall fluid intake, including melons, citrus fruits, grapes, strawberries, carrots, lettuce, tomatoes, celery, and squash. Some sports drinks are good water alternatives for athletes, particularly ones who play hard for long periods of time.

Sodas and other soft drinks which contain caffeine, sugar, and other coloring artificial ingredients are not hydrating and create extra load of sugar which may lead to obesity and diabetes.

For many of the millions who suffer from digestive disorder, it's merely a source of irritation and discomfort; for those with coeliac disease, however, it can be a lot more serious.
Cutely described as the body's "food processor", the long, muscular tube that is our gastrointestinal (GI) tract has the ability to sense and react to whatever passes through it.

And to maintain a healthy digestive system, each of us needs to choose the right food to match our individual GI tract's capacity, says Dr Rajnakova.

Food intolerance or allergy is a primary cause of GI tract problems such as reflu, bloating, dyspepsia, diarrhoea, constipation, diverticulosis, gallstones, fatty liver and even GI cancer. It's no wonder these problems are on the rise, she says, when you look at the modern diet: centred on concentrated proteins from meat and dairy products, preferring simple to complex carbohydrates, and laced with harmful additives.

How do you screen fro gluten intolerance and coeliac disease?

We do a physical examination and take a detailed medical history, plus an evaluation of dietary habits. GI tract prbolems show symptoms that may include nausea and vomiting, bloating, abdominal pain, constipation and diarrhoea. Coeliac disease can be detected by a blood test, after which we would do a gastroscopy do confirm the diagnosis.

Tell us about coeliac disease.

It's an immune-based inflammatory reaction in the small intestine to dietary gluten (the storage protein for wheat, barley, and rye), and it affects those who are genetically predisposed to it.
It's a serious condition: the inflammation caused by the body's reaction to gluten damages the lining of the small intestine, reducing it's absorptive surface area, reducing its digestive enzymes and impairing the absorption of important micronutrients. Apart from abdominal pain and bloating, this causes chronic malabsorption, malnutrition, and unhealthy weight-loss.
In cases of lactose intolerance or coeliac disease, bloating is linked to a failure of the digestive tract to break down nutrients into small, absorbable molecules. Other GI symptoms of coeliac disease include diarrhea, oily stools and flatulence; it can also lead to liver disease, anemia, bone disease and skin disorders. Some coeliac sufferers surprisingly, may have no symptoms at all!

What is the cure?

Excluding gluten from the diet completely resolves the problem. But this is not always straightforward - it often requires detailed patient education, proper motivation, and ongoing follow-up.

Any advice on going gluten-free?

This is interesting! An increasing number of people are going gluten-free, mainly because of the huge misconception that gluten-free food is in and of itself "healthier". In fact, there is no evidence that avoiding gluten is beneficial for people who do not have coeliac disease.
My patients with coeliac disease know that most commercially made gluten-free food is highly processed, low in nutrients and loaded with harmful additives. Instead, I advise them to focus their diet on whole foods that are naturally free from gluten.

I advise anyone who suspects that they or a family member may have a food intolerance or allergy to go for proper medical evaluation and testing.