STRESS AND BODY WEIGHT: AN UNHEALTHY RELATIONSHIP

Introduction

As humans, we are equipped with abilities to handle demands and challenging situations. When these demands are overwhelming, we are said to be stressed. 

Stress is not anxiety, fear or cause of a disease but contributes to some disease development. It is the body's reaction to demands, a state of severe physiological and psychological tension and preparation for fight-or-flight. Fight-or-flight response is the body's biological response to danger. This simply means "battle it out or run ".

During fight-or-flight, your heart rate and blood flow to large muscles increase so you can run faster or fight harder, blood vessels under the skin constricts to prevent blood loss in injury, pupils get dilated to see well. Blood sugar goes up in an attempt to have more energy. 

 At the same time, body processes not essential to immediate survival are

suppressed. The digestive and reproductive systems slow down, growth hormones are inhibited and the immune response is suppressed. Fight-or-flight stress is achieved with the help of cortisol (Stress hormone) and Adrenaline (Fight-or-flight hormone). 

This helped our ancestors survive life-or-death situations commonly faced like an attack by a wild animal. Today the stress we face is more of a psychological origin rather than physical threats. Example are exam tensions, death of a loved one, heartbreak and divorce, money concern etc. 

Whatever the precipitating factor is, the body's response is the same and chronicity alters the normal physiology of the body leading to overweight or underweight. 

WHAT IS STRESS? 🤔

It is a psychophysiological response to actions, circumstances or events that upsets our body's normal state. Theses events can have either a negative or positive impact on us. And these events can either have an Internal or external origin. 

This means that stress can be physical or psychological as the body is in a state of stress when there's ongoing infection, injury, bruise, blow, burn etc. Here, we are more concerned with psychological stress rather than physical stress. 

A stresse is an organism that is stressed. 

A stressor is a condition or Influence that causes stress for an organism. 

Eustress is a healthful, stimulating kind and level of stress. 

Distress means "to constrain".

THE STRESS HORMONE 

A hormone is a regulatory substance produced in an organism to stimulate specific cells and tissues into action. 

Cortisol is the stress hormone and it's secreted from the adrenal glands (Small pyramidal organs above your kidneys) under the influence of Adrenocorticotropic hormone (ACTH) from the front part of your pituitary gland. 

ACTH secretion is stimulated by a hormone called Corticotropin releasing hormone (CRH) from your hypothalamus. 

Cortisol is usually higher in the morning and decreases throughout the day to be drastically lower in the night but in people that work at night, reverse is the case. It's release can be linked to daily activity pattern. Stress causes extra release since it helps the body respond to stress. 

NOTABLE FUNCTIONS OF THE HORMONE INCLUDES:

Regulation of metabolism and controlling blood sugar

Anti-inflammatory action

Cognitive development

Salt and water balance

Blood pressure control 

Child development (Fetal development) 

WEIGHT GAIN AND WEIGHT LOSS 

You may have been wondering if stress actually makes people lose weight or gain weight. Well actually stress does both but this depends on the body's orientation. 

The bones, muscles and fat cells are all affected in the course of action of cortisol. 

CORTISOL AND FAT DISTRIBUTION : VISCERAL OBESITY

When you are stressed, there is prolonged cortisol release. In the tissues, there are enzymes that convert inactive cortisol to the active form and this enzyme is located in the fat (Adipose) tissues. 

Fat surrounding the stomach and intestines (Visceral fat) expresses this enzyme more than subcutaneous (Under the skin) fat cells. In addition, abdominal fat had greater blood flow and four times more cortisol receptors compared to subcutaneous fat. 

All these generally increases cortisol fat accumulating effect and fat cell size enlarging effect in abdomen mainly.  As fat accumulates more around the trunk, this leads to visceral obesity. 

STRESS AND APPETITE: THE EMOTIONAL EATING

When  you are under chronic stress, cortisol influences food consumption by interacting with the brain to stimulate you to crave for food high in fat and/or sugar as well as salty foods. These leads to increase in weight and stress related visceral fat distribution. 

MUSCLE MASS AND CORTISOL

Cortisol being a catabolic hormone is proteolytic ( breaks down proteins). Since muscles are predominantly made of proteins, they are affected and used to generate glucose for energy since in chronic stress, the body is put in survival mode. Cortisol also accelerates this proteolysis so that the body uses muscles as primary source of energy. It inhibits protein synthesis as well. 

So before you decide to build your muscles, you need to note this. 

Having said this, tension-filled individuals who are known to have large muscle mass may be seen slimming down as opposed to effect of cortisol on fat storage and distribution. 

CORTISOL ON BONE 

Elevated cortisol level decreases bone mineral density (BMD) by directly inhibiting osteoblastic activities. Osteoblasts are bone forming cells. The hormone blocks absorption of calcium by bone cells and since bones need calcium for good health, their growth is impaired. With chronic stress exposure, integrity of the bone is impaired contributing to weight loss. 

The bone will as well be predisposed to fracture and osteoporosis. Osteoporosis is a condition where the bones becomes extremely porous and subject to fracture. 

CONCLUSION

The relationship between chronic stress and body weight is not subtle. The enzyme which convert inactive cortisol to the active form is expressed more on obese individuals and this may explain why they are known to increase in weight under stress. Individuals with large muscles mass rather than fat tend to slim down under stressful conditions because of the proteolytic actions of the stress hormone. Effect of the stress hormone on bones can leave the bone unfit to support the weight of the body predisposing the bone to fracture.