Stress & Body Shape: Stress Affects on Body Weight (cont.)
The nucleus accumbens, which is the pleasure center of the brain, responds to most drugs by increasing dopamine and opioid activity. These make us feel good and reduce anxiety and stress. Does sugar do the same thing? Well, it turns out that one dose of sugar to a rat also stimulates the pleasure center, in the same way that drugs do. But repeated doses of sugar don't.
The brain habituates, but there are conditions when the brain doesn't habituate. And the formula for sensitizing this pleasure center so that it doesn't habituate or so that it's more responsive to sweet, high-fat food, is severely restraining the amount of food you eat, at least in rats. Cycles of dietary restraint sensitize the nucleus accumbens. This is partly the work of Bart Hoebel at Princeton.
ELLIN: This is so important, because it almost feels we have no way out of obesity if restraining our eating stimulates overeating, and overeating triggers weight gain. That's why it's so important to have a whole range of tools, to be really sensitive to ourselves, to know when we are hungry, cut back a little bit but not enough to trigger a binge. We need to be able to create a lifestyle that meets our needs for pleasure, relaxation, and satisfaction so we don't have to turn to food.
We developed a method for that at UCSF: The Solution is for adults and Shapedown Program is for children -- you can see the research at www.thepathway.org. All we did was to pump up the skills for stress resilience, to stay in homeostasis. Participants enhanced their skills in understanding how they feel, and what they need so that they can stay above the line more, in homeostasis. This does not mean weight problems are caused by one pathway, such as being depressed and then overeating. Any disruption in homeostasis has the potential to ramp up our appetites.
But we can take action by checking in with ourselves, even five times a day, to see if we're out of homeostasis, out of balance, or not. Just ask yourself: "How do I feel? And what do I need?" It's a great start in decreasing stress and creating that homeostasis, a great way to protect ourselves from deregulating our eating.
MEMBER QUESTION: Relaxation does not curb my desire for sugar. How do I break the sugar cycle?
EPEL: The rat study suggests that restraining and then binging, restraining and then binging, conditions our brain to be overly responsive to sugar. Clearly, rigid, brittle dieting can backfire.
But a moderate amount of dietary restraint is not only healthy; it's also necessary in this toxic food environment. The goal is to have a flexible amount of restraint, and there are skills that can be taught to help people maintain this healthy restraint level.
One problem with dietary restraint is that it takes a lot of energy and mental attention, and if you are putting a lot of cognitive effort into restraining, that means when something else comes up and shifts your attention, you're vulnerable to overeating.
ELLIN: Stress comes in many forms, and one of them is our food environment. There is a center in the brain, the orbitofrontal cortex, that is sensitized to the environment, in how food smells, looks, and tastes. That part of the brain actually produces hunger in response to delicious food. You can feel hungry even when your body doesn't need food, simply by being exposed to a toxic food environment.
MEMBER QUESTION: Is cortisol involved with weight gain? I see lots of commercials for things like CortiSlim and Relacore and they don't seem very trustworthy.
EPEL: You're right. Cortisol can stimulate appetite and, along with high insulin, it also promotes fat accumulation, particularly in the intra-abdominal area. That's because the fat inside of our bellies is extra sensitive to cortisol.
Belly fat has more cortisol receptors than subcutaneous fat -- the fat at our hips and thighs. Excessive cortisol levels over time promote excessive storage of abdominal fat. We have found that cortisol in response to an acute stressor stimulates appetite for comfort food and women with greater abdominal fat distribution tend to show a greater cortisol response to acute stresses.
These women also complain of more life stress. Given these relationships, it is logical to think that reducing stress might reduce cortisol exposure, which in turn might reduce stress eating and abdominal fat. But the data demonstrating this reverse pathway is simply not there. The relationships are probably far more complicated than that. For one, not everyone with high stress has high cortisol. So simply 'reducing cortisol' is not the right target for everyone. The majority of abdominal obesity is not simply explained by chronic stress and cortisol but rather lifestyle.
Antianxiety ingredients in these supplements might possibly help people who are stress eaters, if the products do, indeed, reduce anxiety, but they would likely have tiny effects compared with exercise and cognitive skills training to control eating. I feel very badly for people who have spent a lot of money on these untested products.
MEMBER QUESTION: What specific hormones are affected by food and alcohol?
EPEL: Cortisol responds to food and alcohol and pretty much any stimulant, like caffeine and smoking, but we don't know if these short-term effects have much of an effect on health. It's likely that eating when you are stressed is a risky behavior, because you may have high cortisol from the stress, which can increase insulin, then on top of that, eating increases insulin, as well. The combination of high cortisol and high insulin stimulates hunger, most likely, and reshapes body fat stores -- away from the pear shape toward the apple shape, towards storing abdominal fat. That's Dallman's work, again.
We have found, in our research, that people who identify themselves as stress eaters do, indeed, have higher cortisol and higher insulin during stressful times and tend to gain weight, more than people who identify as stress fasters, or those who eat less when they're stressed. Not only do these people gain weight, but they also increase in the bad type of cholesterol. So we're really worried about the health of stress eaters, more than their weight. Stress eating could be a risk factor for cardiovascular disease.