Although you might not believe it, permanent, long term weight loss isn’t about cutting calories and exercising more. This has been proven in countless studies, and also the countless frustrations of dieters desperately depriving their bodies of nutrition.
So what then is the key to successful weight loss? According to nephrologist Dr. Jason Fung, the solution lies in controlling your body’s ‘thermostat’ — what’s also known as Body Set Weight (BSW).
The Body Thermostat
Think about how a home’s thermostat works to control the desired room temperature: in the summer when it’s hot, the thermostat turns on the air conditioning. In winter, it detects the temperature is too cold, and turns on the heat. The house stays at the perfect temperature despite varying outdoor conditions.
The human body’s BSW, also called an appestat, is essentially a thermostat for body fatness. There are many powerful satiety mechanisms built into our physiology to make us stop eating. For example, the stomach has ‘stretch receptors’ that signal when it’s too full. The body also has powerful satiety hormones, such as peptide YY and cholecystokinin, that stop us from overeating.
The BSW sets an ideal body fatness that it defends just as the house thermostat maintains the temperature. If we’re too skinny, it can trigger the body to gain weight. If we’re too fat, it triggers a higher metabolic rate (total calories burned at rest) to lose weight.
The body tries very hard to maintain its BSW in the original position. This directly contradicts the calories in/ calories out theory that simply eating too many calories causes body fatness, without taking into consideration the BSW, satiety hormones, or other physiological signals. In fact, if you deliberately overeat, your body will try to burn it off.
Think about it: a ‘calorie’ is not a physiologic notion. The body doesn’t have ‘calorie’ receptors and doesn’t know how many calories we eat, or don’t. A calorie of carbohydrate is metabolized entirely differently from a calorie of fat or protein.
Processed food companies heavily push the concept of ‘a calorie is a calorie.’ They want to convince you that 100 calories in a sugary drink is the same as 100 calories in an avocado, in terms of body weight gain. Or that 100 calories of sugar is as fattening as 100 calories of kale.
Consider artificial sweeteners as well. They have no calories, and so fool our taste buds – but they won’t fool our appestat. If all we had to do to lose weight was eat fake sugar and fake fat and zero calories, we’d all lose weight and there’d be almost no obesity crisis, or Type II diabetes crisis. But these are real, despite all the artificial sweeteners.
So what to do?
First, think again about a home thermostat. Suppose it’s set at 70 degrees, but we want the temperature indoors to be 65 degrees. So, we bring in a portable air conditioner. Initially, the temperature will go down – but then the thermostat kicks in and turns on the heat, returning the room temperature to 70. We keep adding more portable air conditioners to cool it down, and the thermostat keeps cranking up the heat to get it back to 70. It’s a futile, no-win battle.
So how about just turning down the thermostat instead?
Decreasing calories to lose weight gets the same result as adding portable air conditioners to cool off a room. Doing so completely ignores the BSW, or thermostat.
Suppose your BSW is set at 150 pounds, but you want to weigh 120 pounds. Conventional advice says cut 500 calories per day to lose 1 pound per week. Initially, your weight may go down to 140 pounds, but then the appestat kicks in to make you gain weight. You become hungrier, and your metabolism slows down in order to regain the weight. So then what do most of us do? Keep restricting calories!
But then what? The body responds again by slowing our metabolism even further. This is a continual fight against ourselves in an ultimately futile attempt to lose weight.
Turn down the appestat or BSW
Obesity is a disease caused by excessive insulin, not excessive calories. In other words, it’s a hormonal imbalance, not a caloric one.
Insulin, produced by the pancreas, does several things. First, it transports glucose (sugar) into our cells to be used in the chemical reaction that creates energy. When more insulin is produced than is needed, the body stores the extra food energy as fat.
When we fast, insulin goes down, and we burn some of that stored energy. That’s we don’t die in our sleep every night!
Just like a room thermostat, the BSW uses a negative feedback loop. What this means: excess insulin leads an increase in the size of fat cells. Fat cells, in turn, produce more of the hormone leptin which then signals the brain that ‘we’re too fat’.
What happens then? Appetite decreases, we stop eating so much, and insulin levels drop. This signals the body to start burning fat instead of eating and storing it, and to return to the original, desired BSW.
The BSW is, in essence, the balance of insulin effect versus leptin effect. In obese individuals, the insulin effect won out over the leptin effect.
This could happen for many reasons, but consider this: Eating foods high in refined grains (not whole), eating frequently, and eating lots sugar, all keep insulin levels high. This happens despite leptin’s best efforts to curb the appetite to lower insulin.
If insulin is extremely low, such as for someone with Type I diabetes, the body loses weight continuously, no matter how many calories the person consumes.
So as fat cells stay over-filled, they produce more and more leptin in an attempt to fight insulin. However, if the root problem hasn’t been addressed – eating too much sugar, too many refined carbohydrates, eating constantly – then insulin levels will continue to rise.
Once a persistently high level of a hormone exists, resistance to that hormone will develop.
Leptin resistance is almost universal in common obesity. With leptin no longer able to keep up the fight, insulin takes over and causes continual weight gain. The insulin vs leptin battle has been lost, and the BSW thermostat is reset upwards.
The key: lower insulin levels
Cutting calories will not reduce insulin’s effect. Instead, the BSW is unaffected and the body desperately tries to regain the lost weight. Eating frequently means constant stimulation of insulin as well.
The key to losing weight then is to help in the Insulin vs Leptin fight. Leptin is already maxed out, so the only thing left is to lower insulin. How to do that?
- Eat less sugar
- Eat less refined grains (whole grains are okay – they have many nutritional benefits)
- Eat moderate protein and more natural fats
- Don’t eat constantly
- Eat more real, unprocessed foods
- Exercise: proven to reduce insulin resistance; builds more muscle fibers; allows excess body fat to be burned for fuel; increases resting metabolism
So there you have it. You don’t need some special diet, expensive supplements, or pre-packaged foods to lose weight. You already have the tools within your own body to get that thermostat down to where you’d like it to be.
About the Author
Laurie Kelly, CPT, RYT-200 is the owner of Dragonfly Drishti Yoga. Formerly a certified personal trainer and nutrition coach with Dragonfly Fitness and Nutrition Coaching, she made the switch to focus exclusively on yoga and ayurveda. She now teaches others how to incorporate yoga, ayurveda and mindfulness practices into their daily lives, and thereby reach their personal wellness and life goals. Contact her here.