Junk food tax? Yes. Mexico will now levy a 5 percent tax on calorie-dense foods. The point is to curb obesity. Gum will be taxed 16 percent. Though why specifically gum as it's not food. There's some dispute as to which country, Mexico or the U.S., is the fattest. But both tip the scales at over 32 percent overweight. Juvenile obesity and related illnesses are escalating. Juvenile diabetes, hypertension, health and liver disease, cholesterol problems--kids are getting these younger and younger. Here are some impacts taxing low nutrition food might have on obesity.Will a Junk Food Tax Cut Obesity? A Weighty Question