Active Low-Carber Forums - Remind me why coffee hinders weight loss?

Early peoples realized that certain plants gave them a little extra energy, stamina and endurance. Humans, always looking to take advantage of a good thing, sought to isolate the special spark that these plants contained –– the compound now called caffeine. With technology came agricultural practices that allowed the cultivation of vast fields of caffeine-containing crops and with selective breeding, the genetic strains could be tweaked to produce plants with higher levels of this magical molecule.
Also, with the knowledge that it was the caffeine, specifically, that provided the desired mind and body effects, isolation of this compound was perfected so that the pure form could be added to any product to impart that special energy burst.

A vast consumer market now exists for caffeinated products. Four out of five Americans consume caffeinated products daily, with an average daily consumption between 100-300 mg. An 8-oz cup of drip coffee contains a little over 100 mg of caffeine, 8 oz. of tea can have up to 60 mg of caffeine and a 12-oz can of soda contains about 40 mg. Consider, though, how small an amount, from our modern super-sized perspective, is this amount of coffee or soda. Also, the caffeine composition of coffees and teas varies with each batch of beans or leaves. The cup consumed today will have a different quantity of caffeine than the one consumed yesterday. It was found that for one major coffee chain, medium-sized servings purchased from the same store differed by 305 mg of caffeine! This makes monitoring and controlling your caffeine intake very problematic. But, should we worry about this at all? Is the black brush with which caffeine has been painted by a variety of health organizations justified?

Known chemically as 3,7-Dihydro-1,3,7-trimethyl-1H-purine-2,6-dione, caffeine is a crystal-forming compound that occurs naturally in tea, coffee and mate leaves as well as guarana paste, cola and cocoa nuts. The most recognized effects of caffeine consumption are increased energy, endurance and mental clarity. Many people cannot meet the criteria of "human" without their morning dose of caffeine and quickly relapse to inanimate object status without continued caffeine intake. However, a too liberal dose of our preferred energizer, produces unwanted effects such as sleep disruption, "the jitters," heart palpitation and increased diuresis.

The mechanism of caffeine's actions is rather simple. The body normally produces a substance called adenosine, which binds to body points called adenosine receptors, and works to slow down nerve cell activity. You get drowsy. Unfortunately for nerve cells, they don't discriminate between an adenosine molecule and a caffeine molecule and caffeine will latch onto these sites like a spinster to a farmhand. Instead of slowing down, the nerve cells speed up. With increased nerve activity, the pituitary gland (the conductor of your hormonal orchestra) is tricked into thinking there is a stress occurring and tells your adrenal glands to produce adrenaline. You go into "fight or flight" response:

Dilated pupils
Dilated respiratory passages
Increased heart rate
Increase in blood pressure
Suppressed appetite
Release of liver sugars into the bloodstream for energy
Tensing of muscles
Sound familiar? All of these effects are designed to promote increased energy and readiness to combat the pouncing tiger, leap from the burning car, or flee the demand-waving tax collector and they have kept us alive and intact throughout human history. Caffeine also stimulates the production of dopamine, one of the body's pleasure-stimulating hormones, so we enjoy the increased energy and receive an additional "happy" feeling from its consumption. We want more and more and more…

The laundry list of benefits of caffeine is actually quite robust. Caffeine helps relieve asthma attacks and vascular headaches by dilating blood vessels and respiratory passages, increases motor activity and short-term memory, increases focus and concentration and increases tolerance to pain. Many diet aids contain caffeine or guarana since caffeine can promote fat burning (thermogenesis) and suppress appetite. And, for athletes, especially endurance athletes, caffeine has been shown to increase stamina, reduce muscle pain/fatigue and enhance overall performance. With such a sterling resume, one would think caffeine to be as important for health and wellness as water, and the populace should lobby for the addition of caffeine as the official 5th Food Group. However, if we more closely examine how caffeine accomplishes these supernatural effects, we see fully why low carb advocates such as Dr. Atkins warn against it for reduced-carbohydrate dieters.

Caffeine promotes the release of fatty acids into the bloodstream; these are the components of a fat molecule that the body can use as fuel. This additional fuel keeps the circulating levels of glucose relatively high and reduces the body's tendency to dip into muscle glycogen as they normally do during exercise. For an endurance athlete, this means that the time before "hitting the wall" is delayed. This phenomenon occurs when the muscles have depleted their store of glycogen and the mobilization of fat for energy cannot occur sufficiently fast to keep the muscles fueled. The fatty acid release permits activity for an extended period of time. Caffeine also promotes the release of adrenaline, which boosts mental clarity, focus and concentration, release of liver glucose, reaction times and motor activity. Again, for athletes such as cyclists and runners, these effects provide significant performance benefit.

For a low carb dieter, though, these effects have a dark and sinister agenda. Consider:
The release of fatty acids as muscle fuel reduces muscle uptake of glucose.
At the same time, adrenaline encourages the release of liver glucose into the bloodstream.
Adrenaline, itself, reduces glucose uptake by cells.
Glucose levels stay high in the bloodstream, prompting continued release of insulin.
In other words, insulin resistance and all of its fat-storing, health-stealing consequences. Moreover, these effects have been noted with quite moderate amounts of caffeine, about that of a mug of drip coffee, and the effects last for hours after the caffeine is administered. To place another nail in the caffeine-addict's low carb coffin, the greater the caffeine devotion, the more debilitating the effects. For heavy caffeine users, it has been found that the pancreas becomes more sensitive and will over-produce insulin in response to the caffeine-elevated blood glucose level. That great villain, hyperinsulinism swoops in to with its sidekick hypoglycemia and the other members of its unholy anti-low carb posse.

Caffeine increases the body's overall level of insulin resistance. For an endurance athlete, this is a good thing and can improve performance. For a low carb dieter, this is the opposite of the golden goal; caffeine is as counterproductive to low carb weight-loss efforts as hiring a pig to guard the peaches. Obviously, the degree of impact will vary with individual, but it is not surprising that many low carb dieters experience stalls or diminished rates of weight loss when they consume caffeinated beverages. For those who simply cannot function without a daily caffeine influx, however, there is a mechanism to reduce caffeine's effects on insulin resistance - exercise. Exercise increases the insulin sensitivity of muscle tissue. This is the problem encountered by endurance athletes. For the low carb dieter, though, exercise can be used to counterbalance, to some degree, caffeine's effects. Plus, one receives all of the health benefits offered by exercise for general wellness and weight loss. To increase motivation to begin or intensify a workout routine, consider caffeine a carrot on a stick.

The ideal situation for low carbers, of course, is the avoidance of caffeine in the first place. It is unwise, though, to completely eliminate caffeine from your diet at one time. The temporarily increased blood flow to the brain can produce vascular headaches and the body must adjust to the new, lower levels of adrenaline, which can produce moderate, unpleasant side-effects such as lethargy, irritability, headache, restlessness and reduced concentration. Many turn back to caffeine rather than endure the withdrawal symptoms (people who say caffeine is non-addictive should be banned like asbestos). Slowly decreasing caffeine consumption will lessen the severity of the withdrawal. Replace a cup or two of regular coffee or soda with their decaffeinated counterparts. Soy coffee has no caffeine, but provides protein and other valuable nutrients. Enjoy green tea hot or cold. Green tea has less than 10% of the caffeine of drip coffee and contains compounds that appear to boost metabolic rate and provide antioxidant benefits. Regardless of the struggle required to reduce, then eliminate, the day's caffeine, the health and diet benefits that await are worth the effort.