It’s All in the Brain: Unlocking the Secrets of Overeating With Neuroscience
As obesity reaches epidemic levels, neuroimaging suggests a link between overeating and brain health—and may indicate new solutions for improving both brain function and eating habits.
Weight problems may be all in your head—or at least in your brain, according to an emerging body of brain-imaging work and related research on cravings, overeating and addictive responses to food. Daniel Amen, MD, one of the world’s best-known neuropsychiatrists, has worked with tens of thousands of patients from 90 countries for more than 20 years and has recently gathered results and insights related to the brain-fat connection in his best-selling book, The Amen Solution: The Brain Healthy Way to Lose Weight and Keep It Off (Crown 2011). IDEA Health & Fitness Association spoke to Amen, a featured speaker at the 2011 IDEA World Fitness ConventionTM, about his research findings and the implications of his work for combating overeating and obesity.
“Most weight problems occur between the ears, which may explain why most diets don’t work and why, after a decade of gastric banding, the success rate is a disappointing 31%,” Amen says. “It’s the brain that makes our eating decisions, and what we’ve found is that there isn’t just one brain pattern associated with overeating—there are at least five. So giving everyone the same diet plan will make some people better and some worse. Instead we’re seeing that we need to match our strategies for overeating to the type of brain pattern or patterns that are affecting us the most.”
The seeds for Amen’s brain-imaging work on overeating came from two of his earlier research projects. The first was a 12-week home study course on anxiety and depression, based on scientific evidence that people could improve mood and reduce anxiety by implementing home strategies. When Amen followed up with the 90 study participants, he found that many felt less anxious, had better memory and focus, and—surprisingly—had lost 10, 20 and even 30 pounds in 12 weeks. In addition, 2009 research presented at the annual meeting of the Society of Ingestive Behavior found that depressed patients who followed a 6-month behavioral weight loss program not only lost weight but also reported significantly less depression.
Amen’s second influential project was the world’s largest brain-imaging/brain-rehabilitation study on active and retired professional football players, conducted at the Amen Clinics to determine the relationship between professional-football participation and brain damage. As football players undertook behavior change programs to improve their brain health, they also lost substantial amounts of weight—as much as 100 pounds.
“We found that changing the brain also changed the body,” Amen says. “Significantly, we also found that as weight goes up, brainpower goes down. The size and function of the brain diminishes as BMI goes up” (see Figure 1).
Additional research has shown that obesity increases the risk for Alzheimer’s disease and other forms of dementia. Amen notes that research from the University of Pittsburgh also found that brains of overweight people—with body mass index (BMI) scores between 25 and 30—had 4% less volume than brains of people with lower BMIs. In addition, brains of overweight subjects looked 8 years older than those of healthy subjects. People who were obese—with BMI scores over 30—had 8% less brain volume, and their brains looked 16 years older than those of healthy people.
“This information should make everyone concerned about their weight,” says Amen. “The brain-fat connection is important. Fat can produce inflammatory chemicals that damage your brain. We found that the larger people were, the smaller their frontal lobes were, and that’s a disaster because the frontal lobes run your life! Not only are we finding that overeating and overweight cause changes in the brain, but we’re seeing that brain patterns can influence how we respond to food.
“It goes both ways. If you have low frontal-lobe activity, as is common with attention deficit disorder (ADD), for example, you’re much more likely to be obese. The frontal lobes are critical to making decisions such as food choices. Given the advertising industry and the current abundance of cheap, unhealthy food, we’re tempted repeatedly. You have to have fairly good self-control to not be obese in today’s society. If your frontal-lobe activity is low, it’s difficult for you to say no.”
Amen notes that although he has been working with brain imaging and with psychiatric patients for over two decades, functional neuroimaging tools have not been used to evaluate overeating and obesity until the last 5 years or so. Single photon emission computed tomography (SPECT), one of the main brain-imaging techniques used at Amen Clinics, looks at blood flow and activity patterns in the brain.
“Using these tools to better understand and treat overeating is very exciting,” says Amen. “I think eventually we will look at all aspects of our behavior to identify the underlying brain patterns, and when we understand [them], we will find natural ways to enhance brain health for effective behavior change. I am personally interested in finding out why people do what they do, and then finding the most effective, natural and least toxic way to treat it. In obesity treatment, for example, gastric bypass can be effective, but it’s expensive and very toxic. There should be other options to try first.”
Amen has had scans done of his own brain to measure progress (see Figures 2 & 3). “My earliest scan, at age 37, showed a toxic, bumpy appearance inconsistent with great brain function, although I rarely drank alcohol and didn’t smoke or take drugs,” he says. “But I had ‘bad brain habits,’ such as eating lots of fast food, living on diet soda, working too much, not getting enough sleep and carrying an extra 30 pounds.”
In contrast, Amen’s most recent scan, at age 52, showed a healthier and younger-looking brain, even though brains typically become less active with age. “I incorporated the same things we do with patients—more exercise, healthier food, appropriate supplements and changes in negative thinking patterns,” Amen says. “It’s very hopeful that we can significantly change the health of our brains by changing lifestyle habits.”
When Amen began doing brain-imaging work in 1991, he was looking for one brain pattern associated with depression, ADD or bipolar disorder. However, he discovered there was not one pattern, but rather multiple patterns, for each condition. Not all people with depression were the same, nor were all people with ADD or all people with bipolar disorder. Similarly, when Amen looked at brain images of overweight patients, he discovered not one brain pattern but at least five—compulsive, impulsive, sad and anxious, in various combinations (see Table 1).
Below is a very brief synopsis of the five brain patterns (more information on each can be found in The Amen Solution: The Brain Healthy Way to Lose Weight and Keep It Off or at www.amenclinics.com).
Brain Type 1: Compulsive Overeater. People of this brain type tend to get stuck on the thought of food and feel compulsively driven to eat. They tend to be nighttime eaters because they worry and have trouble sleeping. They often say they have no control over food. Generally, owing to low levels of serotonin, there is too much activity in the front part of the brain—the anterior cingulate gyrus, or what Amen calls the brain’s “gear shifter”—so these people overfocus on a single thought, such as food in the freezer calling their name. Caffeine and diet pills make them anxious; they don’t need more stimulation. They often feel that a glass (or more) of wine at night could calm them. Compulsive overeaters do best by increasing serotonin levels in natural ways; for example, through exercise and supplements such as 5-HTP, inositol, L-tryptophan, saffron or St. John’s Wort.
Brain Type 2: Impulsive Overeater. People of this brain type have poor impulse control, get easily distracted and reach for food without thinking. Their brain scans show low activity in the prefrontal cortex, which can work as the brain’s “brake.” When effective, the prefrontal cortex stops people from saying stupid things or making bad decisions and helps them decide between the banana and the banana split. This brain pattern is common among those with ADD, which has been associated with low dopamine levels in the brain. Research suggests that having untreated ADD nearly doubles the risk of being overweight. Without proper treatment, it is nearly impossible for people with this condition to adhere to a nutrition plan. Impulsive overeaters need help boosting dopamine levels and strengthening the prefrontal cortex with higher-protein, lower-carb diets, exercise, and supplements such as green tea, L-tyrosine and rhodiola. Any supplement or medicine that calms the brain makes this type worse because it lowers both worries and impulse control.
Brain Type 3: Impulsive-Compulsive Overeater. While this may seem contradictory, it is possible to be both at the same time. Compulsive gamblers, for example, are compelled to gamble and have little control over their impulses. Scans show too much activity in the “gear shifter,” so people overthink and get stuck on negative thoughts. They also have too little activity in the prefrontal cortex and therefore have trouble supervising their own behavior. Impulsive-compulsive overeaters benefit from treatments that increase serotonin and dopamine levels; for example, exercise plus a combination of supplements such as 5-HTP, green tea and rhodiola.
Brain Type 4: Sad or Emotional Overeater. People with this brain pattern overeat to medicate feelings of sadness and to calm the emotional storms in their brains. They often struggle with depression, low energy, low self-esteem and pain symptoms, and tend to gain weight in winter. There is excess activity in the limbic or emotional part of the brain. Sad or emotional overeaters benefit from exercise, from optimizing levels of vitamin D and DHEA (dehydroepiandrosterone) levels and from supplements such as fish oil and SAMe.
Brain Type 5: Anxious Overeater. People with this brain pattern medicate feelings of anxiety or nervousness with food, complain of waiting for something bad to happen and frequently suffer from headaches and stomach problems. Their brain scans often show too much activity in the basal ganglia, due to low levels of the chemical gamma-aminobutyric acid (GABA). These people tend to experience anxiety and a lot of physical tension. The best treatment for anxious overeaters is often to soothe the brain with meditation and hypnosis, in addition to supplementing with a combination of vitamin B6, magnesium and GABA.
It is common to have more than one brain type, and Amen offers treatment options for people who have combinations from the five brain patterns.
Amen has integrated some of his weight loss techniques into a 52-week weight loss program, called The Daniel Plan, at the Saddleback Church, based in Southern California. He is working on the project with Mehmet Oz, MD, and Mark Hyman, MD, and participants have lost over 200,000 pounds so far. “We are finding that yes, people can lose weight, but they need the right plan—one that is tailored for them,” says Amen. “All overeaters are not alike. Not everyone will succeed on a high-protein plan, and not everyone will do well on a higher-carb plan. People need to find what works for them.”
Many of Amen’s overeating treatment methods are based on techniques used in his clinics to treat addiction, and some research has shown similarities between food craving, overeating and addiction.
In some people, food cravings can indicate that the brain’s reward system, an intricate network of brain systems and neurotransmitters critical to human survival, has been hijacked, as happens when a person is addicted to alcohol or drugs.
Neurotransmitters act as chemical messengers relaying information within the brain, and their strength or weakness plays an important role in people’s ability to stop overeating. Four key neurotransmitters are dopamine, serotonin, GABA and endorphins.
Dopamine is the feel-good chemical that becomes less effective when released in high quantities as a result of overstimulation from addictive substances like drugs, alcohol and nicotine. Research suggests that food can also have an addictive effect. In a 2007 study by French researchers, rats were allowed to choose between plain water, water sweetened with saccharin, water sweetened with sucrose (table sugar) and cocaine. After just 1 day of sampling all the options, over 94% of the animals preferred the sweetened beverages to the cocaine, which is considered to be one of the most addictive drugs available. Even rats that were already addicted to cocaine or that received higher doses of the drug continued to choose the sweetened water instead, leading researchers to believe that sugar and saccharin can hijack the brain’s reward system and lead to addiction.
In a 2010 study at Scripps Research Institute, rats were fed a diet of either low-calorie chow or unlimited amounts of junk food. Not surprisingly, the junk food–eating rats displayed compulsive eating habits and, after 40 days, were obese. The junk food diet effectively wore out the brain’s reward system and reduced the rats’ ability to experience pleasure; gradually, the dopamine boost from the fatty foods diminished, and in an effort to keep experiencing it, the rats consumed more and more junk food—one of the hallmarks of addiction.
Sugar, salt and fatty foods have all been shown in some studies to be potentially addictive substances, causing the brain to pump out excessive dopamine, which makes us feel good and increases the importance of these foods in our minds, causing cravings. Exercise is a natural way to increase dopamine.
Serotonin is thought to be the happy, antiworry, flexibility chemical. When serotonin levels are low, people tend to be worried, rigid, inflexible, oppositional and argumentative. Exercising and supplementing with 5-HTP or L-tryptophan are natural ways to boost serotonin.
GABA is an inhibitory neurotransmitter that calms or helps relax the brain. In someone who has suffered an emotional trauma or is under a lot of stress, GABA levels may be depleted and the emotional or limbic brain can become excessively active, making the person feel anxious, uptight or sad. He or she may eat to calm the limbic brain. The amino acid supplement GABA can help, as can vitamin B6, magnesium, lemon balm, kava kava and valerian.
Endorphins are the brain’s own natural pleasure and pain-killing chemicals. They are heavily involved in addiction and loss of control. Cocoa and DL-phenylalanine have been shown to increase endorphin production in the brain.
In a healthy self-control circuit (see Figure 4), an effective prefrontal cortex provides impulse control and good judgment, while the deep limbic system offers adequate motivation for planning and following through on goals. Healthy dopamine levels drive human beings to pursue their passions without getting out of control. When these brain areas and chemicals are in balance, a person can be focused, goal-oriented and able to control cravings.
In the addicted brain, by contrast, the prefrontal cortex is diminished and the drive circuits take control. An underactive prefrontal cortex creates an imbalance in the reward system, causing a loss of control over behavior. Researchers have been studying addicted drive circuits in the brains of substance abusers for many years. Thanks to brain imaging, scientists are now seeing similar brain patterns in people who have problems with gambling, sex and overeating.
For example, researchers at Brookhaven National Laboratory have been using position emission tomography (PET) brain imaging to conduct a series of studies on the inner workings of the brain’s self-control circuit in obese patients. Scans reveal the same patterns of brain dysfunction in these patients as in people addicted to cocaine or alcohol, with lower dopamine levels in the basal ganglia. Other PET studies from this same research team show a correlation between higher BMI and decreased activity in the prefrontal cortex.
Anything that decreases activity in the brain negatively hinders good judgment and makes a person more likely to give in to cravings. Pushing too hard or too often on the brain’s pleasure buttons decreases activity in the prefrontal cortex and can cause the brain’s “brake” to fail. Poor sleep, ADD and head injuries are also associated with reduced prefrontal cortex activity. Many people don’t know they have had a head injury that has affected their self-control.
“Right now we have a confluence of factors—a perfect storm—responsible for the obesity crisis,” says Amen. “Cheap, abundant, unhealthy food, lack of exercise, low levels of vitamin D and omega-3 fatty acids, and enormous portions are some of the problems. Many of us think sugar is a big part of the problem—we had a low-fat craze that turned into a high-sugar craze. But people are becoming more aware of the dangers of sugar. For example, the popular YouTube lecture ‘Sugar: The Bitter Truth,’ by Robert H. Lustig, MD, professor of pediatrics in the division of endocrinology at the University of California, San Francisco, has received over a million hits. Eliminating as much sugar as possible is critical for health and weight loss.”
Based on his research, Amen suggests nine strategies, briefly summarized below, for gaining control of cravings and conquering overeating.
1. Keep Blood Sugar Balanced. Low blood sugar levels are associated with lower overall brain activity and more cravings. These tips can help keep blood sugar levels even throughout the day:
- Consider taking alpha-lipoic acid and chromium.
- Eat a nutritious breakfast every day.
- Eat cinnamon, found to help regulate blood sugars in people with type 2 diabetes.
- Ingest smaller meals throughout the day.
- Stay away from simple sugars and refined carbohydrates.
2. Decrease the Use of Artificial Sweeteners. These sweeteners can be up to 600 times sweeter than sugar and may activate the appetite centers of the brain, making you crave even more food and more sugar. A group of Australian scientists found that alcohol floods the bloodstream faster if mixed with beverages containing artificial sweeteners rather than sugar.
3. Manage Stress. Chronic stress has been implicated in obesity, as well as addiction, anxiety and depressive disorders, and cancer. Consider deep breathing, meditation and hypnosis to combat stress.
4. Outsmart Sneaky Triggers. Identify environmental triggers for unhealthy eating; for example, the mall, the airport, the movie theater or family gatherings; plan to bring healthy foods with you or eat before you go.
5. Find Out About Hidden Food Allergies. These can trigger cravings. If you have an allergy to wheat gluten or milk and you eat wheat or dairy products, the allergy can reduce blood flow to the brain and impair your judgment. Subtle but important food allergies can result in brain inflammation that contributes to poor brain health. Conventional medicine has tended to ignore such reactions, which can occur up to several days after consuming the item in question.
To identify food allergies, eliminate dairy, wheat, sugar, food additives, preservatives and artificial flavorings or colors from your diet for 1–2 months. Then slowly reintroduce these items one at a time every 3–4 days to determine whether a new item triggers problems. When you introduce a food, eat it at least two or three times a day for 3 days to see if you notice a reaction (stop immediately if you do). Symptoms may include brain fog, difficulty remembering, mood issues (anxiety, depression and anger), nasal congestion, headaches, sleep problems, joint aches, muscle aches, pain, fatigue, skin changes and changes in digestion and bowel functioning.
6. Practice Willpower to Retrain Your Brain. Make it a habit to say no to the things that are not good for you. Over time, you will find this easier to do. Long-term potentiation (LTP) is a very important concept here. When nerve cell connections become strengthened, they are said to be potentiated. Whenever we learn something new, our brains make new connections.
7. Get Moving. Research has shown that exercise can help blunt genetic obesity tendencies, improve how the brain uses sugar, reduce cravings and overcome food addiction, handle stress, help you make better food choices and improve brain health overall.
8. Get Adequate Sleep. An expanding body of science has shown that the less sleep you get, the more cravings you’ll have—and the more calories you eat, the more belly fat you’ll have and the higher your BMI will be.
9. Take Natural Supplements for Cravings Control. N-acetyl-cysteine (NAC), alpha-lipoic acid, chromium, DL-phenylalanine and L-glutamine are five good natural supplements that can help take the edge off cravings.
The information in this article is based on interviews with Daniel G. Amen, MD, and adapted with permission from his book, The Amen Solution: The Brain Healthy Way to Lose Weight and Keep It Off. An exhaustive list of references is available at www.amenclinics.com. Stay within your scope of practice and work with qualified health professionals when adding or recommending supplements to your clients’ programs.