Ronald asks: I've heard that chocolate is addictive - is this true? Wynnie says: Chocolate is the most frequently craved food. Many of us will admit to being chocoholics, but are we actually addicted to the chemicals in chocolate or do we crave it because we're psychologically attached? Chocolate does contain substances, such as phenylethylamine, theobromine, anandamide and tryptophan, which trigger mood-enhancing chemicals and neurotransmitters to be released in the brain. Phenylethylamine causes the brain to release a chemical called dopamine in the pleasure centres of the brain, producing feelings of euphoria. But research has shown that most of the phenylethylamine in chocolate is broken down in the gut before it even reaches the brain. Theobromine produces an effect similar to caffeine. Although theobromine is a much weaker stimulant, it can quicken the heart rate, and withdrawal of theobromine can cause migraines. However, levels of theobromine are low, particularly in milk chocolate. Anandamide acts on the same receptors in the brain as marijuana does, causing a person to feel 'high'. But it's likely that most of the anandamide is destroyed by stomach acid long before it reaches the brain. Tryptophan is an amino acid needed to make the neurotransmitter called serotonin. Serotonin improves your mood and makes you feel relaxed. But it's unlikely that chocolate addiction is solely attributed to tryptophan because other foods contain the amino acid too, including carbohydrates. The naughty-but-nice psychological phenomenon partly explains people's craving for chocolate. It's loaded with fat and calories, so we know we shouldn't really eat a lot of it, but at the same time, it makes us feel good. Some people may crave comfort foods like chocolate more during anxiety or stressful periods. Most researchers believe 'chocolate addiction' is not a true addiction. Although chocolate does contain substances which can affect mood, these are found in too small an amount to have any real effect. What's more, similar bioactive chemicals in chocolate can be found in higher concentrations in other foods like green leafy veggies, which aren't so desirable. Scientists suggest that it's a combination of chocolate's nutrients, chemicals and sensory qualities - that is its sweetness, texture and aroma - that explain our craving for chocolate. If you crave chocolate, and you feel as thought nothing but a whole bar will satisfy, new research from the University of Exeter in Britain suggest that a 15-minute walk can help reduce those cravings. Regular chocolate eaters were asked to abstain from eating chocolate for three days. They were then told to either take a brisk 15-minute walk or rest. Volunteers then had to take part in tasks that would normally induce chocolate cravings, including a mental challenge and opening a bar of chocolate. Researchers found that after exercise, volunteers reported lower cravings than after their rest. Ronald's diary: Breakfast: Bread; hi-calcium soya milk Lunch: Rice with meat and vegetables or sandwiches; iced tea Dinner: Rice with meat and vegetables; iced tea Exercises: Volleyball and soccer training every week, push-ups and seat balance exercises every day Wynnie Chan is a British-trained nutritionist. If you've got a question for her or would like to be featured in this column, e-mail nutrition@scmp.com
