Studies on the use of vinegar as an appetite suppressant are conflicting. Some studies show that vinegar affects metabolism, while others show no effect at all. More research needs to be conducted on whether drinking vinegar as an appetite suppressant is safe or beneficial. Talk to your doctor or a dietitian before adding vinegar to your diet.
Vinegar May Help With Fat Loss
A human study published in 2009 in “Bioscience, Biotechnology, and Biochemistry” found that vinegar may independently cause reductions in body fat, regardless of appetite. In the study, 175 obese Japanese subjects who drank a vinegar-containing beverage daily for 12 weeks experienced higher reductions in weight, body fat and waist circumference than those who consumed a placebo. The subjects, who were 25 to 60 years old, drank a 500-milliliter beverage containing either 15 milliliters or 30 milliliters of vinegar in two equal portions: 250 milliliters after breakfast and 250 milliliters after supper. Because the diet and physical activity in each group was the same throughout the study, researchers concluded that vinegar consumption independently led to loss of both total body weight and fat. However, the study did not measure the appetite of the subjects.
Unpleasant Taste May Be a Factor
In two studies published in a 2014 article in the “International Journal of Obesity,” researchers looked at whether vinegar suppresses appetite because of its unpleasant taste. The study groups consisted of young, healthy, unrestrained eaters who were normal weight. In the first study, the researchers tested the effect on appetite when subjects drank a palatable vinegar-containing beverage, an unpalatable vinegar-containing beverage and a non-vinegar control with breakfast. In the second study, subjects drank a milkshake and then tasted vinegar or a placebo without ingesting it. The researchers found that subjects had a reduced appetite after ingesting vinegar as a result of nausea, but tasting the vinegar without ingesting it had no effect on appetite.
Vinegar May Slow Digestion
The fact that vinegar is not palatable and can cause nausea may explain why it is believed to suppress appetite. However, more research is needed to identify what the true mechanism may be. According to a study published in 2007 in “BMC Gastroenterology,” the mechanism may be related to vinegar's ability to slow the emptying of stomach contents, causing one to feel full longer. Researchers found that Type 1 diabetics who had gastroparesis -- a condition characterized by delayed stomach emptying -- experienced even slower gastric emptying after they consumed vinegar. The researchers concluded that this could be a disadvantage for those who need to control their blood sugar.
Other Possible Mechanisms
Another possible mechanism for vinegar as an appetite suppressant is its effect on fat and glucose metabolism. A 2009 study published in "Metabolism - Clinical and Experimental" found that when obese rats consumed a ginseng-vinegar extract, it resulted in a beneficial effect on body weight and metabolism, resulting from a change in how genes involved in metabolism worked. This suggests that vinegar causes metabolic changes leading to weight loss independent of suppressing appetite. However, more studies are warranted on the association between vinegar, changes in gene expression and appetite.