Could drinking coffee all day be making you fat? Caffeine, found in coffee, tea and soft drinks, is the most commonly used stimulant in the world. In addition to providing you with increased mental focus and energy, caffeine also elevates levels of stress hormones in your body, including cortisol. Especially when combined with physical or mental stress, caffeine can cause your cortisol levels to rise too high, leading to uncontrolled weight gain in the abdomen.
Caffeine and Stress
Caffeine has complex effects in your body. The stimulating effects of caffeine are partially due to caffeine blocking the neurotransmitter adenosine, which is responsible for keeping other neurotransmitters in check. Caffeine also stimulates the sympathetic nervous system, responsible for your fight-or-flight response. The sympathetic nervous system leads to the release of stress hormones such as cortisol to prepare your body for dangerous situations.
Cortisol
In the short term, cortisol causes a release of stores of fat and sugar into the blood stream, so that you have energy to either fight for your life or run away from a predator. A 2006 study in "Pharmacology, Biochemistry, and Behavior" found that caffeine increased the amount of cortisol released in response to physical or mental stress.
Weight Gain
When cortisol remains elevated for long periods of time, it can have severe effects on your body. Stress hormones cause your body to store as much energy and nutrients as possible. This leads to a massive increase in fat storage around the abdomen but not the arms or legs. Cortisol-induced fat gain also accumulates around the upper back and neck. In addition, water and salt is stored, causing swelling of the abdomen and large red stretch marks in severe cases. Although caffeine intake itself will not cause massive weight gain, it can contribute to abdominal fat mass as you age.
Caffeine Intake
According to the Mayo Clinic, a moderate intake of caffeine -- 200 to 300 mg, or two to four cups of coffee -- is safe for most healthy men and women. Higher amounts, exceeding 500 to 600 mg can cause jitters and other heath effects. The 2006 study found that three 250 mg doses of caffeine increased how your body responds to stress.
References
- "Pharmacology, Biochemistry, and Behavior"; Cortisol Responses to Mental Stress, Exercise, and Meals Following Caffeine Intake in Men and Women; Lovallo et al.; 2006
- University of New Mexico; Cortisol Connection: Tips on Managing Stress and Weight; C.A. Maglione-Garves, L. Kravitz, Ph.D., S. Schneider, Ph.D.
- Mayo Clinic: Caffeine: How Much is Too Much?
