Despite all my lectures on balanced meals and exercise, today, one of my clients insisted the Coffee Diet is more effective. Astounded, I googled "Coffee Diet" and came up with thousands of results, including 52 published books. Some of these articles claim coffee increases daily caloric burn by 200 to 300 calories, burns more fat reserves, curbs your appetite, and has no negative side effects. By drinking about 5 cups of coffee a day, I will eat less, have more energy, and have an overall better looking body.
CALORIC BURN: How many calories you burn a day is dictated by your size, activity level and BMR (base metabolic rate). Although caffeine is a thermogenic, it does not increase caloric burn enough to make a significant change in weight loss and if it is consumed regularly your BMR has already adjusted. The best way to burn more calories is to increase your caloric burn and/or decrease your food intake.
FAT BURN: I was unable to find any studies concluding that caffeine increases fat burn. Most coffee drinkers use sweeteners which trigger a fat-storing hormone called insulin. At the end of the day, even if there were increased fat burn that simply means that fat was the primary fuel used, not that any fat weight was lost. Focus on overall calorie burn; 3,500 calories equals 1 pound.
CURBS APPETITE: Although caffeine is an appetite suppressor, the effects do not last long and there have been some studies that show appetite may increase over time due to an increase in cortisol levels.
NO NEGATIVE SIDE EFFECTS: There are a few studies out there that suggest coffee consumption may reduce the risk of Alzheimer's disease, Parkinson's disease, heart disease, diabetes mellitus type 2, cirrhosis of the liver and gout. Although there is a strong antioxidant found in coffee, some of the negative side affects stem from all the other chemicals found in the beverage.
See the photo below (2) for additional side effects.
Coffee tastes great and may help you retain your cognitive function as you get older, but it is NOT a diet. There are no quick fixes out there. Work hard and you will see results.