Apple cider vinegar may promote fullness, which can decrease calorie intake.
In one small study of 11 people, those who took vinegar with a high-carb meal had a 55% lower blood sugar response one hour after eating.
They also ended up consuming 200–275 fewer calories for the rest of the day .
In addition to the appetite-suppressing effects of acetic acid, vinegar has also been shown to slow down the rate at which food leaves your stomach.
In another small study, taking apple cider vinegar with a starchy meal significantly slowed stomach emptying. This led to increased feelings of fullness and lowered blood sugar and insulin levels .
On the other hand, some people may have a condition that makes this effect a bad thing.
Gastroparesis, or delayed stomach emptying, is a common complication of type 1 diabetes. Timing insulin with food becomes problematic, since it is difficult to predict how long it will take for blood sugar to rise after a meal.