It doesn’t matter if it’s fresh or squeezed or from a box. Drinking juice at breakfast can stall your fat burner, according to a study in the journal Advances in Nutrition. When people drank OJ at breakfast, their resting fat oxidation – the rate at which their bodies burned fat – fell an average of 20% over the next two hours. Your body prioritises carb burning over fat burning, so when sugar from juice hits your bloodstream, your body works on it first, says study author Dr Jodi Stookey. So if you want to drink juice at breakfast, reduce your carb load by forgoing toast or cereal.