A healthy diet
You have eaten several times a day since you were born, but do you know exactly what you ask of each food? In adolescence the body grows at great speed, and what you eat today shows in your bones, muscles and brain in a few years' time.
Foods and nutrients
When you look at a plate of lentils you see seeds cooked in a broth, but after digesting it your body extracts iron for the red blood cells, protein for the muscles and starch to obtain energy. How does what you put in your mouth differ from the chemical substances that your cells actually use?
Name the groups of nutrients that a complete diet must include (proteins, carbohydrates, lipids, vitamins, mineral salts and water) and state a general function of each…
Name the groups of nutrients that a complete diet must include (proteins, carbohydrates, lipids, vitamins, mineral salts and water) and state a general function of each group in the body.
Explain the difference between food and nutrient, and give two examples of each concept.
Explain the difference between food and nutrient, and give two examples of each concept.
Explain what general function proteins have in an adolescent's body and cite three protein-rich foods.
Explain what general function proteins have in an adolescent's body and cite three protein-rich foods.
The food wheel
The food wheel shows several food groups labelled with letters, with larger sectors indicating a greater presence required in the daily diet. State which letter occupies…
The food wheel shows several food groups labelled with letters, with larger sectors indicating a greater presence required in the daily diet. State which letter occupies the sector that should dominate our diet, which food group it corresponds to, and which letter indicates the group whose consumption should be occasional.
The Mediterranean diet is considered a healthy model. Describe its main characteristics (predominant foods, primary fat source, consumption frequency for each group) and…
The Mediterranean diet is considered a healthy model. Describe its main characteristics (predominant foods, primary fat source, consumption frequency for each group) and compare it with the typical diet of many teenagers today.
Organising meals according to needs
A healthy diet combines variety, water as the usual drink and foods of good nutritional quality. Spreading meals out helps to organise the day, but there is no energy figure or compulsory distribution that is valid for every teenager: growth, activity and personal circumstances all play a part.
Explain why breakfast is considered an important meal, especially for school-age children, and describe a balanced breakfast indicating which nutrients are provided by…
Explain why breakfast is considered an important meal, especially for school-age children, and describe a balanced breakfast indicating which nutrients are provided by each food item you include.
Name the five meals a day that are recommended and explain why it is advised to spread food intake over several meals instead of one or two very large ones.
Name the five meals a day that are recommended and explain why it is advised to spread food intake over several meals instead of one or two very large ones.
A 14-year-old female athlete needs about $2200\ \text{kcal}$ per day. If her breakfast provides about $450\ \text{kcal}$, calculate what percentage of her daily energy…
A 14-year-old female athlete needs about $2200\ \text{kcal}$ per day. If her breakfast provides about $450\ \text{kcal}$, calculate what percentage of her daily energy intake is covered by breakfast and reason whether it complies with the recommendation that breakfast should provide around $25\ \%$ of daily calories.
Reading labels: sugars and salt
It is advisable to prioritise varied foods, with plenty of plant-based foods, and to limit products with too much salt, free sugars or poor-quality fats. «Processed» does not always mean unhealthy: tinned cooked pulses can form part of a balanced diet.
Explain what ultra-processed foods are, how we can recognise them when shopping, and why their consumption should be limited even though they are tasty and cheap.
Explain what ultra-processed foods are, how we can recognise them when shopping, and why their consumption should be limited even though they are tasty and cheap.
The nutrition label on a packet of biscuits indicates that every $100\ \text{g}$ contains $20\ \text{g}$ of fat, $65\ \text{g}$ of carbohydrate (of which $30\ \text{g}$…
The nutrition label on a packet of biscuits indicates that every $100\ \text{g}$ contains $20\ \text{g}$ of fat, $65\ \text{g}$ of carbohydrate (of which $30\ \text{g}$ are sugars) and $6\ \text{g}$ of protein. The WHO recommends that free sugars should not exceed $10\ \%$ of daily energy. Knowing that $1\ \text{g}$ of sugar provides about $4\ \text{kcal}$ and that a teenager consumes about $2200\ \text{kcal}$ per day, calculate how many grams of these biscuits would reach that limit if they were the only source of sugar for the day, and comment on the result.
A can of sugary soft drink ($330\ \text{ml}$) and two whole oranges provide practically the same amount of simple carbohydrates (about $35\ \text{g}$). However, health…
A can of sugary soft drink ($330\ \text{ml}$) and two whole oranges provide practically the same amount of simple carbohydrates (about $35\ \text{g}$). However, health guidelines advise against the soft drink because it provides "empty calories", while they recommend the regular consumption of whole oranges (but not squeezed and strained into juice).\na) Justify the concept of "empty calories" by contrasting the complete nutritional composition of both foods (micronutrients, fibre, and water).\nb) Predict and compare how the blood glucose curve will evolve after consuming the soft drink versus the two whole oranges, explaining the role of dietary fibre in the rate of absorption and in the sensation of satiety.
Back to the beginning: From each food you ask for specific nutrients: proteins and calcium to build growing bones and muscles, and carbohydrates or healthy lipids to provide the steady energy your brain needs.