Martial artists who smile before the start of a match are more likely to lose. This could be as a smile can convey fear or submissiveness.

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It's almost impossible to get too much sugar from fresh fruit. While the sugar in fruit is mostly fructose and glucose (fructose is what's converted into fat in your body), you can't get too much sugar from fresh fruit. Fresh fruit contains a lot of fibre and water which slows down your digestion and makes you feel full.