This is the 4th in a series of posts all having to do with weight loss, diets, eating appropriately, and losing weight the correct way. Keep reading for more on how you can slim down, firm up, and watch the numbers on the scale fall.

Since I’ve alluded to this before, its time to explain the connection between stress, carbohydrate consumption, and weight gain and understand the physiological processes.

Stress = Cortisol

During times of anxiety, stress, or nervousness, the body’s sympathetic nervous system takes over, putting us into fight-or-flight mode. When that happens, cortisol is produced, digestive and immune systems shut down, and the body switches to burning only glucose or glycogen for fuel.

Why this is a problem:

  • Cortisol & Hormones: When cortisol is produced, especially over a long time, the body steals from other hormones, thus disrupting the endocrine system.
    • A disrupted endocrine system affects the thyroid, which is responsible for metabolism.
    • This also reduces production of Human Growth Hormone, a key to muscle mass, strength, and youth.
    • Another hormone that is robbed by cortisol is dopamine, the hormone responsible for contentment and happiness.
      • Reduced dopamine levels heighten the need for comfort through vices or addictions, which for many people is food, and that’s one cause of stress-induced eating.
  • Stress & Digestion: By shutting down the digestive system, the body reduces production of digestive enzymes and stops pushing wastes to the colon, which allows wastes to stagnate, turn into toxins and remain in the body. Without proper removal of toxins (done by the liver and immune system), to protect the body from the harmful nature of toxins, the body surrounds toxins with fat tissue.  Thus fat accumulates to protect the organs from toxins.
  • Stress & Immune System: As the immune system is down-regulated in fight-or-flight mode, less toxins are identified and cleared from the system, which means they remain in the body causing free-radical oxidation and attracting fat.
  • Stress & Glucose: During perceived emergencies the body doesn’t have time to go through the involved process of converting fat into usable fuel so it uses blood glucose then glycogen. This drop in blood sugar makes us feel hungry, irritable, and crave sugary things to replenish blood glucose as fast as possible.
    • If sugar is not replaced through external sources quickly enough, since the liver can’t convert fat to fuel during fight-or flight mode, the next fastest source of fuel is protein in muscle. This is means stress can decrease muscle mass, which is one of the key determinants of metabolic rate.

Cortisol is also the prime culprit of abdominal fat, encouraging the storage of fat around the torso instead of dispersing it across the body.

Clearly stress works through many physiological processes happening in the body and brain to move the body toward weight gain and fat accumulation.  This was a survival mechanism of early humans required for evolution when the only stressors were predators or threat of famine.

Unfortunately our stress can last for hours or even days on end, which means our body stays in this mode for far too long, even through multiple (often unhealthy) meals.

Carbohydrates = Insulin

When dietary carbohydrates are consumed, they raise blood sugar, and this happens even more strongly and quickly in the case of foods with a high glycemic index (sugar is higher than beans).  Spikes in blood sugar cause an equal rise in insulin levels (in non-diabetics). Insulin acts to transform blood sugar, known as glucose, into glycogen, which gets stored in the liver and muscles for quick energy.

  • Elevated levels of insulin cause the liver to make more fatty acids.
  • Insulin inhibits the breakdown of adipose tissue (fat) for energy.
  • After insulin has converted all the glucose into glycogen, blood glucose falls again.  If this stimulus-response mechanism happens too intensely and too quickly, blood glucose can fall too low leading to ‘fake’ hunger, felt as sugar cravings, low energy, brain fog, and irritability.
    • Low blood sugar pushes us to indulge these cravings to satisfy the brain’s need for fuel, and when that happens the blood sugar-insulin roller coaster starts again.
  • When all the glycogen stores are full, but glycogen still exists unused, it must get transformed into fat. Fat stores do not have a limit and can continue to grow as a result of excess glycogen.

For weight maintenance or loss, daily carbohydrate intake should ideally be below 100 g to prevent this cycling.  This is why diets such as Atkins, Dukan, Paleo, or Slow Carb can be so effective when followed correctly.

Stress + Carbohydrates

The deadly combination.

First, with stress and high insulin levels the body can no longer use stored body fat for energy.  In fact, it seeks to create more of it.

Second, while the blood sugar roller coaster is certainly carbohydrate-induced, it is worse in the case of stress.  As we learned, stress may act on this in 2 main ways: dropping blood sugar levels and dropping dopamine levels.  In both cases, we seek sugary items to replenish blood sugar and to raise dopamine levels.  When such cravings are indulged, they body follows Pavlov’s Dogs reactionary tendencies and the cycle self-perpetuates.

High stress -> High cortisol -> Low blood sugar -> Cravings -> Eating -> High blood sugar -> High insulin -> Excessive glycogen -> Fat conversion and storage.

High stress -> High cortisol -> Low blood sugar -> Cravings -> Eating -> High blood sugar -> High insulin -> Low blood sugar -> Cravings …

As you can see its a dangerous cycle. And that cycle, repeated over and over due to ongoing stress and poor food choices, leads to (often uncontrollable) weight gain.

Even independent of each other, stress and (excessive) carbohydrate consumption can lead to fat storage and weight gain, but when they are combined, they equal a deadly combination.  Literally deadly due to the connection between chronic stress, abdominal fat, and metabolic syndrome, which includes heart disease, diabetes, high blood pressure, cholesterol, and triglycerides.


The body is series of complex systems that work together in an effort of self-preservation.  Thus it is difficult to simplify and explain such intricate mechanisms.  But I hope I’ve made the cortisol + insulin = weight gain connection a little more clear.

Feel free to leave questions below and I’ll do my best to answer them.