Your genes may help explain why you put more sugar in your coffee and on your cereal than other people do. A new study of 1,900 twins and their siblings reports that about 30% of variations in sweet taste perception can be attributed to genetics. People who perceive sweet taste less strongly may add more to satisfy their sweet tooth. Researchers tested four sweeteners, including two non-nutritive options, but found no difference between them, suggesting a single mechanism for sweetness perception regardless of calorie content. The findings were published in Twin Research and Human Genetics.