Hmmmm, parties. How much can you eat? Vol-au-vents, fruit cake, crisps, pizza, mince pies with brandy butter and a mound of chocolates. Wash it all down with a load of fizzy drinks then give it a good spin on the dance floor. Don’t be surprised if you start feeling sick! After you have eaten you may not want to dance - instead you might begin to feel sleepy. A number of changes occur in your body when you have just eaten. Blood is diverted to the stomach, ready to absorb the nutrients from the food, and away from your muscles, discouraging physical activity. The brain rapidly absorbs some of the nutrients in your food, converting them into chemicals which affect how we behave. After eating a meal rich in protein, such as fish, the brain can produce chemicals including dopamine which keep us alert. After eating a meal containing lots of carbohydrate, such as pasta, the brain produces a different chemical, serotonin, which makes us drowsy. Eating too much can lead to indigestion, as can eating too quickly or having too many fizzy drinks! The stomach contains hydrochloric acid which is vital for food digestion, but sometimes too much is produced causing it to seep up and out of the stomach into the food pipe. Urgh. Since stomach acid is strong enough to corrode metal, this not surprisingly hurts! To stop the pain we need to neutralise the acid by taking something alkali like sodium bicarbonate, normally used in baking.

	Understand that bloated feeling!
	Unfortunately, taking sodium bicarbonate to reduce the amount of acid in your stomach can make you feel so bloated that you think your stomach’s about to burst. To understand why this happens (and to discover a cunning way to blow up balloons without losing your breath) you will need a small empty plastic bottle, sodium bicarbonate (bicarbonate of soda), lemon juice (or vinegar) and a balloon.
	Put about three teaspoons of sodium bicarbonate in the bottom of the empty bottle.
	Pour in about 25 millilitres of lemon juice – enough to cover the sodium bicarbonate and a bit more.
	Very quickly stretch the neck of the balloon over the top of the bottle - you may want to ask someone to help you, one person to pour and the other ready with the balloon.
	Hold the neck of the balloon tightly on to the neck of the bottle. The balloon will begin to fill with gas. Sometimes it helps if you blow up the balloon first and then empty it, as this stretches the rubber.
	Why?
	The sodium bicarbonate reacts with the acid in the lemon juice releasing carbon dioxide. This carbon dioxide fills the balloon, just as carbon dioxide produced by stomach acid and sodium bicarbonate fills your stomach and pushes it outwards. You may notice that loads of foam has built up in the bottle – this foam also forms in your stomach if you swallow the bicarb, creating trapped gas. The only way to get rid of it, and make you feel less bloated is to belch (but make sure you say pardon afterwards!).