By Kate Kelland LONDON (Reuters) – A planned levy on sugary drinks due to be introduced in Britain in April 2018 could significantly reduce the number of people who become obese and develop diabetes and tooth decay, scientists said on Thursday. In a study on the levy’s health impacts, researchers found the positive effect would be greatest if the drinks industry responds by reformulating products to cut sugar content, rather than keep the same formulations but raise prices to consumers. The planned levy is tiered, starting from no tax on diet and low sugar drinks, a low tax on mid-sugar drinks containing 5 to 8 grams (g) of sugar per 100 millilitres (ml), and a high tax on very sugary drinks containing 8g or more per 100 ml.