Why is it that stress causes weight gain for some, whilst for others it just falls off? Both responses make sense based on our physiology. It may all be down to how often we are triggered, at what level and for how long?
Historically our survival threats were freezing, starving or being eaten so our nervous system has evolved to help us cope with this type of stress. Acute stress triggers cortisol. This raises sugar levels in the blood stream to provide energy for finding food, fighting or running away. In today’s modern world this inbuilt response doesn’t serve us so well. We have central heating and air-con for temperature control. We are often sitting down all day at computers, not using our limbs to run or hunt which means sugar levels in the blood stay high. This can only be tolerated temporarily as the maximum capacity for sugar (glucose) in the blood is 5 -10 ml.
For conversion to energy the glucose must enter our cells which requires insulin. If the cells don’t require extra energy due to low energy demands, or insulin resistance, it must be removed from the blood by the liver. Small amounts can be stored here, or in muscle tissue, as glycogen but the remainder is converted to fat.
Our survival mechanisms influence subtle chemical and hormonal changes. Metabolism may be slowed to conserve resources or appetite raised to incur fat storage for warmth, or long-term energy. In times of food scarcity the body is primed to store fat. Modern diets often lack nutrient density and ultra processed foods can contain non-food items which confuse the body. This can be interpreted by the body as starvation which along with low calorie or yo-yo dieting may mistakenly trigger our fat storage programmes.
The inherent fight or flight response removes energy from our internal organs driving it to our limbs and heart so we can take action. This also triggers cortisol to breakdown tissue for energy. This is the origin of the weight loss we see in highly stressed individuals. Over time though, if we are constantly stressed, the organs responsible for keeping us healthy are deprived of energy. Essential processes like digestion, immunity, detoxification and organs such as the liver and heart may malfunction. Continual glucose stimulation tends to lead to insulin resistance and fat storage (see above) which is all linked to weight gain. To lose weight your organs need to function well, especially your liver which directs the utilisation, storage and generation of both glucose and fat.
It is thought that chronic (long-term) mental stress also activates our survival instincts. Overthinking and negative thoughts are interpreted by the subconscious as real. The brain can’t distinguish between our worry and an actual event. Scientists think chronic stress by-passes our normal stress circuitry so cortisol production stays switched on. The result is excess tissue breakdown and poor repair. This can lead to inflammation, poor appetite control and insulin resistance, ending in an overall collapse of our energy management processes (metabolism) and the accumulation of fat.
I always think that part of the weight loss equation is to make your body feel safe to lose weight, so that your body’s genetic fat storage programmes are not triggered. Regardless of how your body responds to stress, we focus on nourishing the body and working with ingrained stress responses to turn the fat storage triggers off. We gently convince it that weight loss is the right course of action.
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