In a recent study published in the American Journal of Clinical Nutrition, the long-term effects of caffeine on weight loss were examined over a 12 year period in a study. It was found that long-term consumers of coffee weighed about 1 pound less after 12 years.
Does this mean that drinking coffee is a useful weight loss strategy? Not necessarily.
WATER WEIGHT OR FAT LOSS?
For one thing, we are only talking about a very modest difference in weight of one pound. For another thing, coffee acts as a diuretic, which means a substance which causes you to pass more urine. That means that very likely, the weight loss noted in the study and then some is due to decreased water weight, not fat.
In fact, coffee might very well cause you to put on weight, particularly abdominal fat, the kind which is associated with increased risk for diabetes, heart disease, and high blood pressure.
COFFEE AND INSULIN
Drinking coffee causes the pancreas to produce more insulin, the hormone which causes excess carbohydrates to be stored as fat.
In a double blind study done at Duke University, diabetics who took capsules containing caffeine saw their average daily sugar levels in the blood go up by 8 per cent. The authors of the study theorized that caffeine interferes with the process that moves glucose from the blood and into muscle and other cells in the body where it is used for fuel. The caffeine in coffee might also trigger the release of adrenaline, which is the 'fight or flight' hormone that is known to boost sugar levels.
That's not all. Because drinking coffee causes insulin spikes, the extra insulin eventually converts the sugar in the blood to either fat or energy, resulting in low blood sugar. When people have low blood sugar, they feel the need to eat substances that will increase their blood sugar levels, such as refined carbohydrates, coffee, or both. Of course, this leads to weight gain, not weight loss.
COFFEE, CORTISOL AND LACTATE
Drinking coffee causes the body to secrete cortisol and increases the production of lactate.
Cortisol is another hormone that's part of the fight or flight response. Animal and human studies have shown that high levels of cortisol are associated with cravings for sugar and fat, increased appetite, and weight gain, rather than weight loss.
Lactate, on the other hand, is known to increase anxiety, which in turn causes the body to secrete still more cortisol. In a study performed at the West Virginia University School of Medicine, 10 healthy volunteers were injected with 3, 5, or 7 mg of caffeine. Researchers found that there were dose-related increases in ratings of anxiety and blood levels of cortisol and lactate. In one case, a volunteer had a full blown panic attack.
In this article, I've only discussed the implications of coffee consumption on weight gain and weight loss. I haven't even gone into the overall health risks of coffee, which include kidney stones, gout, exhausted adrenal glands, decreased immune response, arthritis, osteoporosis, acid reflux, insomnia, migraines, heart disease, diabetes, and so on.
The bottom line is, if you're serious about healthy weight loss, there are better choices for weight management aids than coffee.