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Optimum Sports Nutrition

Dr. Ann de Wees Allen
Dr. Ann is the Chief Of Biomedical Research at the Glycemic Research Institute and the Director Of Sports Science at Human Performance Laboratories.
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Can Coffee Make You Fat?

Q. I saw you on FOX television, where you said, “Coffee can make you as fat as a pig!” How’s this possible if the coffee doesn’t contain any milk, cream, or sugar? Do sweeteners make this situation worse?

A. Coffee’s ability to make you fat has nothing to do with the added creamer or sweetener. Plain black coffee can make you fat. Though I discovered that coffee and caffeine triggered fat storage in human fat cells in the 1980s and that coffee/caffeine impaired blood glucose levels, thus triggering a metabolic cascade of negative physical events in the human body, more current independent research has validated my original findings.

For many years, I felt like I was banging my head against a brick wall in maintaining my position that coffee and caffeine are fattening. Luckily, research caught up and validated my original research, including the American Diabetes Association and the American Journal of Clinical Nutrition:

Even decaffeinated coffee has been proven to acutely impair glucose metabolism in healthy young men. So, clearly the pathogenesis of plain coffee—without caffeine—stimulates blood glucose imbalance and impacts adipose tissue fat production.

Drinking regular coffee also causes secretion of cortisol, a stress hormone and biochemical marker of stress that triggers belly-fat accumulation. Dr. Henry Kahn of the Emory University School of Medicine states,

“There’s something about fat cells in the body—the way they respond to stress hormones. People with high levels of stress hormones have a tendency to store fat in their bellies.”

We’ve all seen the commercials on TV ranting about cortisol and belly fat. Stress activates cortisol, and so does the consumption of coffee and caffeine. I have yet to see a magic pill sold on TV that can control cortisol, since stress and ingestion of cortisol-elevating foods and beverages are the main cause of cortisol elevation in humans. Avoiding the stimulation of cortisol is important in keeping body fat levels low.

The biochemical disruptions caused by drinking coffee and/or caffeinated drinks (such as energy drinks) are related to their glycemic properties. Coffee elicits an acute insulin-insensitive environment in both healthy and obese individuals, and in type 2 diabetics. Researchers at Duke University Medical Center stated that

“Daily consumption of coffee, tea, or soft drinks raises blood sugar levels and may even hinder efforts to control the condition [blood-sugar elevation].”

Coffee and caffeine-containing energy drinks mediate negative effects on glucose tolerance and glucose homeostasis in humans via adenosine receptor antagonism, and impairment of insulin-mediated glucose uptake via caffeine-stimulated epinephrine release. Both coffee and caffeine stimulate the release of epinephrine, which exerts actions opposite to that of insulin via beat-adrenergic stimulation. Simply put, elevating blood sugar and/or insulin levels in humans causes weight gain via adipose tissue fat cells.

Here’s the bottom line: Drinking coffee and/or caffeine energy drinks disrupts weight loss and elevates cortisol-driven belly fat. So, avoiding coffee and caffeine-related blood glucose excursions and cortisol elevation is mandatory in keeping fat cells at bay.

In diabetics, coffee and caffeine beverages have adverse effects on glucose metabolism, producing higher average daytime glucose concentrations and exaggerated postprandial glucose responses. Additionally, athletes should never drink coffee or caffeine products before exercise because of the risk of adverse cardiovascular events.

So, should we give up coffee? No, because coffee has multiple health benefits, and the only drawback of ingesting coffee is the triggering of weight gain, increased belly fat, and glucose imbalances. Here are a few tips for enjoying coffee’s benefits while minimizing its drawbacks.

  1. Adding skim milk to coffee in a 50/50 ratio can help decrease coffee’s negative effects.
  2. Don’t add non-dairy creamers to coffee, as this only makes fat cells happier and fatter.
  3. Don’t use flavored coffee creamers and flavored coffee.
  4. Adding sugar, honey, or artificial sweeteners only makes coffee act crazier, so just add skim milk (50/50) to help buffer fat-cell activation.
  5. Yes, energy drinks that contain caffeine fall into the same category of coffee.
  6. Keep cortisol levels low. Avoid stressful people and situations when possible. When not possible, excuse yourself and go for a one-mile run to get away from them. They probably won’t follow you.

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