Would it be possible to live healthily on only a few types of food?
Yes, but it gets harder the fewer foods you allow. To stay healthy you need carbohydrates, fats and proteins -and not just any proteins, but a mix containing all 22 amino acids from which your own proteins are built. You need trace elements, vitamins and minerals as well. Avocados reputedly include all these, but not in the right proportions, so you'd need to choose additional foods carefully.
What's the evidence linking sugar to cancer risk?
There's long been anecdotal evidence linking higher sugar consumption with an increased risk of cancer. Doctors working in Africa during the 20th century noted how increasing consumption of refined carbohydrates and sugar by the indigenous populations led to increased risk of what they termed the 'diseases of civilisation', such as diabetes, heart disease and some forms of cancer. More scientific evidence has emerged from studies involving comparisons of the blood glucose levels of huge numbers of people and their cancer risk.
In 2005, a study of 1.3 million Korean people pointed to a link between sugar consumption and cancer risk, as did a European study published in 2010. However, the evidence is still far from compelling, as the increased risk figures are small and possibly attributable to other lifestyle factors.
Why does your tummy rumble when you're hungry?
The technical term is 'borborygmus' and it's the sound of your stomach and intestines contracting. This occurs continuously, as part of the normal digestive process: your stomach squeezes to mix your food with the gastric juices; your intestines contract to move food along on its journey. When your stomach is empty, the borborygmus is louder because you're squeezing air back and forth and the empty space resonates. B But there's also a wave of contractions called the 'migrating myoelectric complex', which runs from the stomach to the small intestine, between an hour and 90 minutes after eating. This is designed to help sweep out any leftover indigestible bones, seeds and toenails, and also to keep the intestinal bacteria down in the lower intestine, where they belong.