Stress Eating and Carbohydrate Cravings:
Dr. Chrystyne Olivieri March 2019
It is not uncommon among Americans to state “you want me to give up carbohydrates? Then what’s left to eat?” I hear this statement a lot from my patients with diabetes as well as those with prediabetes and the obese. If you agree with this statement, then you are certainly eating way too many carbohydrates since there is really plenty left to eat! It is well established in the literature that stress eating (eating when not hungry) is associated with sugar and simple carbohydrates. Does anyone feeling super stressed and say “boy, I’d kill for some broccoli right about now”?
So, it’s pretty safe to say that stress eating is associated with sugar and simple carbohydrates. These foods include, but not limited to, things like sweets: candy, cake, cookies, ice cream (includes frozen yogurt), and simple carbohydrates like: bread, cereals, oatmeal, pasta, macaroni, noodles, popcorn, chips, pretzels, rice, corn, potatoes and french fries. But first, we really need to understand what stress is in our modern world.
Throughout over 2 million years of human evolution, our ancestors had to deal with stress, however their stress was very different from what we experience in our modern culture. The human body is very well adapted to deal with acute stress. This is the kind of stress we would encounter if we ran into a “bear” who wants to eat us. Or the stress of hand-to-hand combat during a battle for territory or power. Our physiological responses to stress have insured our survival as a species. These chemical processes during acute stress enable our senses to become sharper (vision and hearing), our muscles to get the energy to run away or stay and fight (fight or flight model) and our brains to not “over-think” the situation.
So, let’s say one of our ancestors encounter a bear while looking for the wild raspberries they were told about. This is the chain of events that will happen, called the HPA Axis (Hypothalamus/Pituitary/Adrenal) response to seeing a growling bear ready to pounce:
1) The adrenal glands release adrenaline and cortisol, the fight or flight hormones
2) Cortisol releases stores of sugar from the liver to use as immediate energy
3) In response, the heart pounds, the pupils dilate, the airways open wide and the body shifts blood to the muscles (takes it away from other vital organs temporarily)
4) The brain has the “fear & alert center’ activated by sending signals to the parts of the brain (amygdala and the prefrontal cortex) responsible for impulse control and rational thinking and down regulates them (puts them on hold temporarily) and turns up the part of the brain which increases aggression (locus coeruleus) and makes us ready for anything!
5) The immune system increases internal inflammation which is designed to reduce blood loss if physical injury occurs
All this is great for acute stress and prepares the human body with the ability to deal with this
stress really, really well. The problem is that modern humans really don’t need this stress response in our modern world.
But what happens if we come home to a “bear” every night or every morning at work? Or other chronic stressors like poverty, chronic illness, traffic, financial or relationship problems? Our response to stress is the same physiological response described above, whether it’s acute or chronic. The problem is our bodies are not designed well for chronic stress. Chronic stress also does not have the need for “heightened vision and hearing” as well as “blood to our muscles so we can run away or stay and fight”. And we certainly don’t need the brain chemistry changes which down regulates impulse control and rational thinking and up regulates aggression! But we get this anyway.
This stress response is also frequently associated with carbohydrate cravings, or “stress eating”. If you need the blood sugar to produce immediate energy (fight or flight), this is excellent! But, what happens when we eat too many carbs that we actually don’t need? We gain weight and have insulin levels rise in response to the rise in blood sugar from the carbs. When the cellular energy supply becomes overloaded, this actually impairs the mitochondria in each cell (think of them as the furnace, creating heat and energy) from processing energy efficiently. This leads to fatigue and eventually, insulin resistance. Belly fat grows but we become more and more fatigued, so we eat more carbs, thinking that that will give us energy (since that is what we were led to believe). Which eventually leads to more insulin resistance, then prediabetes and then Type 2 Diabetes.
Type 2 Diabetes is epidemic in our modern world. However, the human body was never designed to have high levels of sugars and simple carbohydrates in our diet. And based on what we know of our ancestors, our human DNA has not changed much in the last 40,000 years. Looking back in human history, where did sugar and carbs even come from 10,000 years ago?
There were not many carbohydrates available in most environments, but fat and protein were usually plentiful. When our ancient ancestors ate sugar, mainly from seasonal fruits, they would gorge and hopefully gain 20-40 pounds, mainly belly fat accumulation. Fruit was about the only carbohydrate available (capable of increasing insulin levels), and is still associated with increased insulin release when over-consumed. But what follows the fruit season is winter. Historically, human beings have ensured their long-term survival with the accumulation of belly fat from elevated fruit intake and subsequent elevated insulin levels (the hormone of fat storage) which made mid-winter starvation less likely. The individuals who gained more belly fat had a better chance to pass their genetics on to the next generation. This is the basis for the “Thrifty Gene Theory”.
Although this theory makes a lot of sense in the ancient world, it doesn’t help us at all in the modern world. We don’t live that kind of lifestyle any longer. But we do have the same DNA. We need to eat to our modern lifestyle and deal more appropriately with the chronic stress all around us. And relieving that stress by giving in to sugar and carb cravings will never work. Giving in to carb cravings can initially reduce our stress (think “comfort foods”), but it sets us up for longer-term and more chronic stress. One of the stress hormones is cortisol. The main role of cortisol is to allow the release of sugar from the liver. Unfortunately, belly fat promotes cortisol to release sugar from the liver all the time, not only when it is needed (like if you don’t have time to eat). So just having a lot of belly fat will actually keep you fat, until you decide to cut way down on the carbs, or better yet, eliminate them entirely. Then you will no longer have sugar and carb cravings.
Research on food cravings has revealed that a craving will last only about 30 minutes. If you can distract yourself or remove yourself from where the food is (perhaps take a 30-minute walk outside) the craving will likely pass. You may return after your walk to find you’re not craving any longer. If it comes again, do the same thing. If you can resist several cravings in a row over a few days, you will find that each consecutive craving is weaker and weaker. Eventually it will stop. This is what people have found when they make the decision to cut out sugar and high carbohydrate foods, like deciding to “go Paleo”. Then you may find you only have a craving once a week or even less. The more you indulge a craving, the stronger it will become; and the less you indulge a craving the weaker it will become.
The real answer to handling stress and sugar cravings is to make sure your body gets all the nutrition required to run a healthy, human body. That can be found using the Paleo Diet. And reducing stress through daily exercise, good quality sleep every night, positive social connections to others that are supportive to you and using mindfulness or other forms of meditation and spirituality is the functional way to health and happiness.