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Columns: Health Yourself

Addicted to food

By Victor Katch
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In this month’s “Health Yourself” column I want to discuss the possibility that many of us may be addicts. Food addicts, that is.

In trying to explain why some people seem to be “hooked” on different foods leading to obsessive behaviors, excess calorie intake, and subsequent unwanted weight gain, researchers have uncovered what many of us have suspected for years: Certain foods predispose themselves to physical and emotional addiction. Our food dependency resembles the addiction to drugs like alcohol, heroin, meth, and cocaine.

Are you addicted? Take the food addiction quiz below and then read on to learn more about the similarities between food and drug addiction.

Food addiction quiz

  1. I find myself consuming certain foods even though I am no longer hungry: a) Never b) Once a month c) 2-4 times per month d) 2-3 times per week e) 4 or more times per week.
  2. I worry about cutting down on certain foods:  a) Never b) Once a month c) 2-4 times per month d) 2-3 times per week e) 4 or more times per week.
  3. I feel sluggish or fatigued after overeating: a) Never b) Once a month c) 2-4 times per month d) 2-3 times per week e) 4 or more times per week.
  4. I have spent time dealing with negative feelings from overeating certain foods instead of spending quality time with family, friends, and colleagues at work/play: a) Never b) Once a month c) 2-4 times per month d) 2-3 times per week e) 4 or more times per week.
  5. I have had physical withdrawal symptoms (i.e., agitation and anxiety) when I cut down on certain foods. (Do not include caffeinated drinks.): a) Never b) Once a month c) 2-4 times per month d) 2-3 times per week e) 4 or more times per week.
  6. My behavior regarding food and eating causes me significant distress: a) Never b) Once a month c) 2-4 times per month d) 2-3 times per week e) 4 or more times per week.
  7. Issues related to food and eating decrease my ability to function effectively in my daily routine: a) Never b) Once a month c) 2-4 times per month d) 2-3 times per week e) 4 or more times per week.
  8. In the past 12 months I kept consuming the same types or amounts of food despite significant emotional and/or physical problems related to my eating.___Yes ___No
  9. In the past 12 months I have found that eating the same amount of food does not reduce negative emotions or increase pleasurable feelings the way it used to.  ___Yes ___No

YOUR RESULTS:
To meet the food addiction threshold, you must answer Question 6 or 7 with (d) or (e); AND you must answer at least three of the other seven questions in the following way: Questions 1 and 2 (d); Questions 3, 4, and 5 (d) or (e); and Statements 8 and 9 (Yes).

Junk food junkie?

I’m not talking about becoming addicted to a bunch of apples or mounds of cabbage. No, I’m talking about a mountain of chips, a whole bag of cookies, a gallon of ice cream, a 16-ounce soda, or even a thick, juicy steak. These “hyperpalatable foods,” which are high in sugar, saturated fat, and often salt, are the foods most associated with addictive properties.

Nobody chooses to be a heroin addict. No one sets out to be an alcoholic. And no one wants to overeat, especially when they know it’s bad for them. Addictive behaviors arise out of a primitive neurochemical reward system in the brain that seems to override normal willpower and overwhelms ordinary biological signals. Increasingly, researchers are focusing on identifying individuals and substances (foods or ingredients) that predispose to addiction.

Experiments with animals (mostly rats) show signs of dependence when exposed to sugar for only a few hours per day. When exposed to excess sugar, they overeat and exhibit increased tolerance, meaning they eat more and more each day. When the sugar is removed the rats show signs of withdrawal like increased anxiety and tremors. Rats even show evidence of craving sugar—they’re willing to work harder to get sugar than other foods. Some of the same symptoms and behaviors are showing up in animal experiments using high-fat, good-tasting foods.

Human experiments suggest similar findings with calorie-dense foods high in fat and sugar. Among college students surveyed about food cravings and dependency, 40 percent (males) to 60 percent (females) report strong cravings for foods that are high in sugar and fat.

Similarities between addictions

The diagnostic criteria for substance dependence found in the psychiatric diagnosis codebook (the DSM-IV) correlate surprisingly well to food addictions. For example, here are seven of the major diagnostic criteria used for drug-related addiction along with the food addiction analog:

  • Substance is taken in larger amounts and for longer periods than intended. (A classic symptom in overeaters.)
  • Persistent desire or repeated unsuccessful attempts to quit. (Describes the repeated attempts at diet-induced weight loss by the overweight.)
  • Much time/activity is spent to obtain, use, or recover. (Similar to the repeated attempts at different weight-loss schemes.)
  • Important social, occupational, or recreational activities are given up or reduced. (Many overfat people suffer the same fate.)
  • Use continues despite knowledge of adverse consequences. (Most overfat people know about diabetes, cardiovascular disease, and stroke, yet continue to overeat.)
  • Tolerance-marked increase in amount; marked decrease in effect. (Most overeaters eat more and more just to feel “normal” or to avoid withdrawal.)
  • Characteristic withdrawal symptoms; substance taken to relieve withdrawal. (The same physical withdrawal symptoms occur with sugar withdrawal.)

The science of food addiction

In 2001 scientists at the Brookhaven National Laboratory published the first-of-a-kind study called “Brain Dopamine and Obesity” (Lancet, 2001). The results were stunning! Very obese individuals had lower levels of dopamine in the reward areas of their brains than did people who were normal weight. In fact, the brain scans of the obese showing reduced dopamine receptors were precisely the same as those observed in cocaine/heroin addicts and alcoholics.

Dopamine is a neurotransmitter. It sends signals that motivate us to eat (and engage in sex and other rewarding behaviors). It reflects wanting more than liking more. Animals that lack dopamine starve to death because they have no motivation to eat.

At first, it seemed conflicting that overfat individuals and those with drug addiction had reduced dopamine levels. If dopamine makes you want to eat or take drugs, why would addicted people have less of a dopamine response when they eat or take drugs? It was first believed they were addicted because they were more sensitive to the rewarding effects of dopamine—they should have more dopamine release, in this case. But it’s just the opposite. Less reward makes them want more. It was concluded that people who don’t get much reward from food or drugs want more and more because they are never satisfied!

Evidence of food addiction

A growing body of research on food addiction (particularly sugar and fat) in animals and humans mounts. Here are some examples.

  1. Sugar stimulates the brain’s reward centers through the neurotransmitter dopamine, exactly like other addictive drugs.
  2. Brain imaging of overweight food-addicted individuals and drug-addicted individuals shows lower numbers of dopamine receptors, making both more likely to crave their substance of choice (sugar, fat, heroin, etc.).
  3. Foods high in fat and sugar stimulate the release of the body’s own opioids called endorphins (morphine-like chemicals) that reinforce increased consumption of hyperpalatable (processed) foods.
  4. Drugs used to block the brain’s receptors for heroin (naltrexone) also reduce the consumption and preference for sweet, high-fat foods in both normal-weight individuals and obese binge eaters.
  5. People (and rats) develop a tolerance for sugar, hence they need more and more to be satisfied, just like the case with alcohol or heroin.
  6. Obese individuals continue to eat large amounts of unhealthy foods despite severe social and personal negative consequences, just like addicts or alcoholics.
  7. Animals and humans experience “withdrawal” when suddenly cut off from sugar, just like addicts detoxifying from drugs.
  8. As with drugs, after an initial period of enjoyment, the user no longer over-consumes the substance to get high, but rather to feel normal.

The bottom line

While research on food addiction is in its infancy, the evidence mounts that overeating may dampen the dopamine response, and hence increase the overeating response leading to dependency (addiction). And it should surprise no one that the foods most often implicated in food addiction are those calorie-dense foods high in sugar, fat, and probably salt.

Sources:
• Rudd Center for Food Policy and The Food Addiction Library
• Gearhardt, A.N., et. al., 2009. “Preliminary Validation of the Yale Food Addiction Scale.” Appetite, 52(2): 430-436.
• Colantuoni, C., et al., 2001. “Excessive Sugar Intake Alters Binding to Dopamine and Mu-opioid Receptors in the Brain.” Neuroreport, 12(16): 3549-3552.
• Volkow, N.D., et al., 2002. “‘Nonhedonic’ Food Motivation in Humans Involves Dopamine in the Dorsal Striatum and Methylphenidate Amplifies this Effect.” Synapse, 44(3): 175-180.
• Ebbeling C.B., et al., 2004. “Compensation for Energy Intake from Fast Food Among Overweight and Lean Adolescents.” JAMA, 16: 2828-2833.
• Kessler, David A. “The End of Overeating: Taking Control of the Insatiable American Appetite.”

Victor Katch

Victor Katch

VICTOR KATCH has been active in the exercise, nutrition, and weight control arena for more than 40 years at the University of Michigan. He earned his undergraduate degrees in international relations (political science) and physical education (kinesiology) from California State University at Northridge. He also did undergraduate work in international relations at the prestigious University of Uppsala in Sweden. Katch's graduate degrees are from the University of California, Berkeley. He is a professor in movement science in the School of Kinesiology. He has four children and four grandchildren, and is an avid exerciser who enjoys year-round walking and jogging with his wife, Heather, and playing golf whenever possible, weather permitting.

COMMENTS

  • Micaela Cleary - 1989

    You didn’t mention nicotine addiction. Same thing? I kicked the suger/fat addiction by substituting nicotine like a million other people. Hmmm.

    Reply

  • David Thomas - 1963

    Victor may not be addicted to fat, sugar or salt, but apparently he is addicted to golf, fortunately, a positive addiction…. unless his wife feels that his many golfing absences are not good for their relationship.

    Reply

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