How the body responds

The link between stress and weight gain is receiving a great deal of media attention these days and you might be wondering whether all this hype is actually based on fact? The “Shape up for Summer Programme” takes a holistic view on your health – healthy body – healthy mind – healthy spirit – so read on!

One of the first points to consider is how different people handle stress. For some, stress is highly motivating and somehow they are able to dig deeper, reach higher and achieve what they didn’t dare dream was possible. Others don’t feel they can cope and respond by grabbing the closest box of chocolates as pressure rises.

Clearly – the relationship between stress and eating behaviour is complex and varies from individual to individual. Questions that frequently arise regarding stress and food are: Does stress…

• actually reduce our willpower?
• increase our appetite?
• increase our risk of suffering from serious health problems ie cardiovascular disease, diabetes etc?

What happens when we are stressed? The hypothalamus (part of the brain) sends a signal to the adrenal glands to release cortisol whether that stress is physical or emotional. Cortisol, in turn releases glucose (sugar) and fatty acids into the bloodstream in order to provide energy to the muscles so they can respond to the stress. Too little cortisol release can result in hypoglycaemia (low blood sugar), whereas an excess of released cortisol can cause hyperglycaemia (high blood sugar), which if persistent and chronic, could lead to diabetes.

Researchers Greenspan and Baxter, 1994, also report that high levels of cortisol can increase appetite and food intake and later fat deposits in the trunk and abdominal area, producing the “spare tire” with which many are so familiar! What happens with chronic stress is that the cortisol levels remain elevated for long periods of time.

This can lead to “overworked” adrenal glands resulting in less cortisol release i.e. a blunted effect. Scientists Rosmond et al, 2000 having researched this area extensively, suggest that overworked adrenals may trigger a vicious cycle of hormonal imbalances, possibly linked to dysfunction of the heart and increased obesity in men. The same effect has frequently been found in women.

Therefore chronically elevated cortisol appears to be associated with diabetes, high blood pressure, obesity and cardiovascular (heart) disease. However, research also indicates that there may be a link with mental disorders, such as depression.

The table below gives more detail about how the stress hormone cortisol affects the body:

• regulates carbohydrate, fat and protein metabolism
• affects muscle tone and microcirculation
• raises blood pressure
• increases gastric secretion
• alters connective tissue response to injury
• impairs cartilage repair
• increases inflammation
• shrinks lymphatic tissue
• increases allergic and immunological responses
• stimulates the central nervous system
• increases appetite and fat deposits especially in the cervical area, trunk and abdomen
• increases the risk for developing diabetes

Stress and Eating! Not only can stress increase our appetite, it typically makes one crave foods that are calorie laden and lacking in nutrients. Some “stress-eaters” go for high-energy foods containing sugar and fat (e.g. chocolate), others prefer salty foods (e.g. savoury chips) and then there are those who choose crunchy foods (e.g. potato chips, crackers).

Some people initially lose their appetite when facing a stressful situation, but typically about 40% of these individuals begin to eat excessively about 6 weeks after the onset of stress, ultimately putting on weight (Simonson 1990).

See part 2 for positive coping mechanisms.

Remember to follow your "Shape up for Summer Programme" and you will feel the difference.

By Kathleen Mc Quaide (exercise physiologist and educationalist): Health Promotions Manager at the Sports Science Institute of South Africa (SSISA) and OptiFit Walk and Run Health Programme Director. For more information about the health, wellness and fitness services offered at SSISA, visit our website http//:www.ssisa.co.za or phone 021 659 5600.