Why Diets Fail (Because You're Addicted to Sugar) (13 page)

Personal testimonies provide compelling evidence of addiction to certain foods, in particular refined or processed foods that include sugar, other carbohydrates, fat, salt, and caffeine. In fact, individuals who identify themselves as “refined-food addicts” reveal that the symptoms of addiction to these types of foods mimic the criteria doctors use to diagnose substance dependence.
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However, while these qualitative accounts add important information to the study of the addictive nature of some foods, personal testimonies alone are not sufficient to determine the existence of an actual disorder or syndrome.

To empirically determine whether the addiction model can be applied to overeating, researchers have recently developed a survey that uses the
DSM
criteria for substance dependence; however, instead of asking individuals about drugs, the survey asks about behaviors and emotions related to food. With the use of this assessment tool (called the Yale Food Addiction Scale),
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researchers have found increasing evidence of addiction to palatable foods in
humans. Research using this newly developed scale suggests that food addiction is apparent in a variety of groups. It can be detected in individuals who are normal weight, overweight, obese, or severely obese. For instance, 41 percent of patients who are extremely obese, to the point that they are seeking surgical treatment to help them lose weight (for example, bariatric surgery), have also been found to meet the criteria for a food addiction.
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Participants in studies that have used this scale show addiction-like symptoms such as tolerance, withdrawal, eating despite negative consequences, and failed attempts to limit consumption of certain foods. Although the scale is designed to assess addiction to food in general, not specifically to sugar, it is important to note that the foods listed as being particularly problematic to individuals are overwhelmingly carbohydrates (sugar-based foods). This supports previous research that has suggested that obese individuals with problematic eating tend to go for foods that are high in sugar.
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The brief questionnaire on the opposite page was adapted from the Yale Food Addiction Scale. Answer the questions and then evaluate your answers using the scoring instructions to determine whether you meet the criteria for food addiction.

What does it mean if you are addicted to food according to the scale? First, don’t worry. This does not mean you are doomed to be a sugar addict forever. Once you discover the causes of your addiction and learn how to control your urges to eat sugar-rich foods, you can break free from it. The plan that we describe in part two of this book will help you wean yourself off of excess sugars and carbohydrates. We give you the tools you need to accomplish this without sacrificing eating out, socializing with friends, or other food-related events that normally derail a diet. We’re going to help you handle your addiction in the chapters to come.

If you don’t meet the criteria, that’s fine, too. Everyone can benefit from cutting the sugar from their diet; whether you are technically addicted or not, reducing your sugar intake is going to make a big difference to your health.

ARE YOU ADDICTED TO FOOD? TAKE THE TEST AND FIND OUT
.

The following questions ask about your eating habits in the past year. People sometimes have difficulty controlling their intake of certain foods such as sweets, starches, salty snacks, fatty foods, sugary drinks, and others.

In the past 12 months …

1. I find myself consuming certain foods even though I am no longer hungry
.

0 - Never

1 - Once per month

2 - 2-4 times per month

3 - 2-3 times per week

4 - 4+ times per week

2. I worry about cutting down on certain foods
.

0 - Never

1 - Once per month

2 - 2-4 times per month

3 - 2-3 times per week

4 - 4+ times per week

3. I feel sluggish or fatigued from overeating
.

0 - Never

1 - Once per month

2 - 2-4 times per month

3 - 2-3 times per week

4 - 4+ times per week

4. I have spent time dealing with negative feelings from overeating certain foods, instead of spending time in important activities such as time with family, friends, work, or recreation
.

0 - Never

1 - Once per month

2 - 2-4 times per month

3 - 2-3 times per week

4 - 4+ times per week

5. I have had physical withdrawal symptoms such as agitation and anxiety when I cut down on certain foods. (Do not include caffeinated drinks: coffee, tea, cola, energy drinks, etc.)

0 - Never

1 - Once per month

2 - 2-4 times per month

3 - 2-3 times per week

4 - 4+ times per week

6. My behavior with respect to food and eating causes me significant distress
.

0 - Never

1 - Once per month

2 - 2-4 times per month

3 - 2-3 times per week

4 - 4+ times per week

7. Issues related to food and eating decrease my ability to function effectively (daily routine, job/school, social or family activities, health difficulties)
.

0 - Never

1 - Once per month

2 - 2-4 times per month

3 - 2-3 times per week

4 - 4+ times per week

8. I kept consuming the same types or amounts of food despite significant emotional and/or physical problems related to my eating
.

Yes / No

9. Eating the same amount of food does not reduce negative emotions or increase pleasurable feelings the way it used to
.

Yes / No

Scoring Instructions:

You meet the criteria if you answered 4 to question 1 or 2
.

You meet the criteria if you answered either 3 or 4 to questions 3-7
.

You meet the criteria if you answered yes to question 8 or 9
.

To meet the food addiction threshold, people must meet the criteria for either question 6 or 7 and the criteria for 3 or more of the other questions (1-5, 8-9)
.

How Food Addiction Changes Your Brain

Evidence of food addiction in humans also comes from studies investigating indicators of addiction in the brain. Researchers are somewhat limited when it comes to understanding the exact neurochemical changes that occur in human brains, largely because we don’t have many tools to test these changes in people. This is why the preclinical, or animal, research is so important. In order to study the brains of humans, researchers use brain-imaging techniques called functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) scans. In studies that use these techniques, human participants volunteer to have their brains scanned in one of these machines (although it might sound scary, it is completely safe and painless). Functional magnetic resonance imaging technology measures blood flow in activated regions of the brain to detect neurological responses to stimuli. Positron emission tomography scans are similar but instead allow for the generation of images that show neurotransmitter receptor–specific activity occurring in the human brain.

Using fMRI technology, food addiction has been associated with increased brain activation in reward-related regions when anticipating palatable food. Interestingly, increased activation of an area of the brain called the anterior cingulate cortex was found when participants with high food addiction scores were anticipating palatable food.
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This is similar to the type of brain activation that has been observed when cigarette smokers are shown smoking cues, like images of cigarettes.
^21
,
22

Some studies have also shown changes in dopamine in reward-related brain regions in humans who are obese. Using PET technology, for example, researchers have found evidence that indicates that obese individuals may have less dopamine receptor availability,
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a finding that has also been observed among individuals with drug addiction. This finding lends support to what is called the reward deficiency syndrome, which is based on the hypothesis that some people may have a lower-functioning reward system and, as a result, may feel as though they have to eat more to experience the reward response produced by food. A competing theory, called the hyperresponsiveness model, is that certain individuals are highly sensitive to reward, and because they may find eating more pleasurable, they engage in it more often.
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And it may all boil down to the genes that we are born with. Imagine that one individual is born with a dulled reward response. To be reinforced by food, he may feel that he has to consume more food than normal. This is an example of the reward deficiency syndrome hypothesis. Imagine that another individual is born with a highly sensitive reward system. Because food may be experienced as more rewarding for this individual, he may tend to overeat. This second scenario is an example of the hyperresponsiveness model. There is evidence that points toward each of these theories, which complicates the bottom line: are people overeating because their brains are overly or less responsive to reward?

To help make sense of what may appear to be inconsistent ideas, another theory has emerged called the dynamic vulnerability theory.
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This theory proposes that an individual may be born with increased sensitivity to reward; however, after a period of overconsumption (which can be tied to both his genetics and the environment), his reward response may become dulled. This dulling of the reward response is in essence the brain change that underlies tolerance. As a result of this dulled reward response, he may continue to
overeat in an effort to experience the pleasant feelings he previously felt while eating. Support for this theory comes from studies in children and adults which show that overweight individuals report increased reward sensitivity, whereas obese individuals report decreased reward sensitivity.
^26
,
27
Thus, it may be that initially, food is especially rewarding to some, but with increased weight and, therefore, possibly continued overconsumption, the sensitivity of their reward responses may decrease.

Another explanation for these conflicting theories may be that there is a difference between reward responses that are associated with anticipation of food and those that are associated with consumption of food, as these have been shown to vary. Evidence using fMRI technology suggests that individuals with food addiction may show more brain activation in reward-related regions when anticipating highly palatable food, but mixed responses when they actually consume the food.
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It has been proposed that these individuals may want the food but may not necessarily like the food, perhaps due to dysfunctional reward mechanisms. For instance, some individuals may no longer experience a great feeling of reward when consuming food, perhaps due to a decrease in certain dopamine receptors, but they may still expect to be rewarded from food, so they show activation in reward regions of the brain when anticipating food nonetheless. This disconnection between wanting something but not actually liking it can also be seen in the drug abuse literature, where addicts will show great desire to obtain the drug of abuse, but the euphoria from taking it is not as great over time.
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