Types of Food And what they do…

WALT: Know the names of the 5 food types, and know their jobs WALT: Know the names of the 5 food types, and know their jobs. understand why each food type is important. group foods into types. Investigate Carbohydrates in more detail by experiment with Starch

Carbohydrates… (starch and sugar) Give us steady energy and keep us full up. The energy is easy for our bodies to use, so lots of athletes eat carbohydrates before races and training. You should try and eat carbohydrates every meal…

Proteins… Help our bodies grow and repair themselves. Without protein, you won’t have a strong body because your muscles won’t develop. You’ll also take longer to heal when you injure yourself… People who eat meat get lots of proteins from the meat that they eat. Vegetarians need to eat nuts and things like quorn to give them protein.

Dairy… Dairy provides calcium. Your body needs calcium to help keep bones and teeth strong and healthy. Be careful though… some of dairy like ice-cream and cheese is high in fat, so you shouldn’t eat too much!

Fruit and Vegetables… Fruit and vegetables provide fiber and vitamins. Fiber is important for out digestive system. Vitamins help keep you fit and healthy- they create an army which can fight off bugs and bacteria. You should eat at least 5 portions of fruit and veg each day…

Fats and sugars… Fats and sugars help provide energy. Our bodies are really clever, and store the spare energy from fats until your body needs it, but you shouldn’t eat too many fats! Sugars provide short bursts of energy, which don’t last for very long and might make you a little hyperactive!

So how much should you eat? This plate shows you how much of each food group you should eat each day…

Starches, Sugars and Fats Sometimes foods are classified into starches, sugars and fats. Starches includes foods like potatoes and provide mainly carbohydrates. Carbohydrates give us the energy to carry on with our day-to-day lives. Foods high in sugars include those naturally occurring as in fruit, and those containing refined/processed sugars such as sweets, chocolates, cakes etc. We need to limit our intake of refined sugars – these are empty calories which give an immediate ‘boost’. A small amount of fat is important for health, but eating too much fat is unhealthy. It leads to clogged arteries (restricted blood supply), high cholesterol and becoming overweight.

Now, let’s look at Starch in more detail… Starch is a carbohydrate. It is found in plants. Green plants make carbohydrates through photosynthesis. Starch is therefore in many foods, but also in other things as well, e.g. some paper. Starch is a white powder. Starch reacts with iodine to produce a blue or blue-black colour. It can therefore be used as an ‘indicator’, i.e. to test if starch is present in something.

Experiment Add a few drops of iodine solution to each of the items and observe the change of colour of the iodine (if any). Anything that turns blue-black contains starch. Care with iodine – close adult supervision; handle with care - do not get into mouth, etc. Store the tincture of iodine away from the classroom. Care with clothes – iodine can stain. Wash hands after activity.

Results Item Prediction Did iodine turn blue or blue/black Was there starch in the item? Grapes sugar Tissue Kitchen paper plastic bread weetabix apple biscuit Sweet potato Lemon