The Relationship between Obesity and Stress

Obesity Related Stress Management

Stress is a widely used term, yet the concept of stress in humans is difficult to define. Whilst generally perceived as a negative phenomenon, not all stress is bad; indeed a certain amount is necessary for us to function optimally. However, when most people talk about feeling stressed, they are referring to a negative state induced by the feeling of being placed under mental or emotional pressure. Stress itself is not an illness, but chronic stress can have a detrimental effect upon physical and mental wellbeing, and is one of several environmental factors associated with obesity.

What is the Human Stress Response?

The human stress response involves the nervous, immune and endocrine systems. During exposure to a source of stress or stressor, the adrenal glands, located on top of the kidneys, release a surge of catecholamine hormones including adrenaline and noradrenaline to which the sympathetic nervous system (SNS), responsible for controlling respiration, heart rate, hormone release, blood pressure and digestion, reacts to prepare the body to mount an attack or flee from the source of danger: the so-called “fight or flight” response. Heart rate, blood pressure, perspiration and mental activity are increased and the coronary arteries, bronchial passages and vessels supplying blood to the limb muscles dilate, whilst any bodily functions not essential to immediate survival, such as digestion and reproductive function, are suppressed.

What are Hormonal Changes Associated with Stress?

Increased secretion of the hormones thyroxine and tri-iodothyronine by the thyroid gland serves to raise overall metabolic rate, leading to increased respiration, thermogenesis (heat production), heart rate and intestinal motility. Thyroxine also acts upon the brain at cerebral level and can induce anxiety and difficulty sleeping.

The adrenal cortex is stimulated to increase production of the hormone cortisol, which signals the release of fats and glucose from adipose tissue into the blood stream. The effects of insulin - the hormone responsible for moving glucose from the blood stream into cells for storage - and its secretion by the liver’s beta cells are simultaneously inhibited in order to ensure that the fats and glucose in the blood stream remain readily available for use as an energy source by the tissues that need them. Elevated cortisol levels also act to reduce the production of lymphocytes - a type of white blood cell integral to immune function – as well as reducing inflammation and raising arterial blood pressure.

When the source of stress is no longer present, the parasympathetic nervous system (PNS) takes over to restore respiration, heart rate, metabolic and other functions to their normal state, known as homeostasis.

Chronic Stress and the Toll on the Human Body

The human stress response provided our ancestors with a means of surviving direct threats to their physical wellbeing. Today, few people in the US find themselves under physical attack on a regular basis. Instead, stressors tend to be psychological or emotional in nature. Whilst certain aspects of the stress response may be beneficial in the short-term, providing the stamina and focus needed to meet a deadline, or the ability to make a quick decision under pressure, exposure to modern sources of stress is frequently protracted and failure to return to homeostasis can carry serious health consequences.

The cognitive effects of chronic stress include impaired memory and accelerated cognitive ageing. Chronically elevated heart rate and blood pressure can lead to cardiovascular disease, and the presence of cortisol in high levels is associated with excessive quantities of circulating cholesterol, which is a known risk factor for atherosclerosis. Cortisol is also associated with increased risk of central obesity.

Long-term exposure to stress may indirectly lead to ill-health due to stress-related immunosuppression, which can leave the body vulnerable to attack from pathogens. There also is evidence to suggest that psychological stress can trigger or exacerbate immune-mediated disorders such as eczema and psoriasis, multiple sclerosis and rheumatoid arthritis.

The Complex Relationship of Stress and Obesity

Chronic stress is a known risk factor for obesity, but the direction of causality has yet to be established. Elevated levels of basal sympathetic nervous system activation have been observed in those with metabolic disorders such as diabetes, which are common in obese individuals, and there is some evidence to suggest that elevated basal SNS activation may be predictive of obesity.

The effects of stress upon appetite and dietary preferences vary between individuals, with some people experiencing weight gain during periods of stress whilst others report reduced appetite. Weight status prior to onset of stress has been found to be predictive of individual response, with those who were already carrying excess weight more likely to experience weight gain than non-overweight individuals. The reasons for this are not yet fully understood but it is thought that the elevated levels of insulin typically observed in overweight and obese individuals may be implicated.

Individuals who do gain weight in response to stress typically report craving calorie-dense “comfort foods” that are high in fat and sugar, known to act upon opioid receptors in the brain to inhibit stress responses. Studies have also found that individuals under high levels of stress tend to snack more, eat fewer main meals and fewer portions of vegetables. A tendency towards reduced participation in physical exercise has also been observed, although it is not clear whether a sedentary lifestyle exacerbates stress or whether stress promotes physical inactivity.

Lack of eating awareness, also known as unconscious or mindless eating, can contribute towards obesity and is associated with a stressful lifestyle. Workplace stress in particular is linked to increased fast food consumption and eating whilst performing other activities (task eating).

Identify your Sources of Stress

Stressors vary greatly between individuals, depending not only on lifestyle and personal circumstances but on how a potential source of stress is perceived and what meaning is attached to it. A situation or event that constitutes a significant source of anxiety to one individual could be seen as a positive challenge or source of motivation by another. Typically, the greater degree of control an individual feels they have over a particular event or situation, the less likely it is to be experienced as stressful.

Social stress, including factors such as low socioeconomic status, workplace stress and poor work-life balance, personal conflicts with friends and family and caring for a sick loved one, is the most commonly reported source of stress and is associated with a tendency towards weight gain and central adiposity. Major life events such as death of a loved one, divorce or relationship problems, dismissal from work or change in job, pregnancy, marriage and personal injury or illness can also generate significant levels of stress.

Stress can be caused by internal conflicts such as having to make a difficult decision or feeling equally drawn to two conflicting goals or desires. Other internal factors that can contribute towards stress include setting unrealistic goals, having low self-esteem and being unduly self-critical.

Stress Management Techniques

Individual ability to cope with stress frequently determines whether a potentially stressful experience is experienced as positive or negative. Strategies for dealing with stress fall broadly into two categories: those that aim to remove or reduce the impact of a stressor by tackling it directly and those that focus on ways to reduce the effects of stress irrespective of its source. Fostering practices that promote overall wellbeing, such as eating healthily and getting enough sleep can also help to reduce stress.

Consider Keeping a Stress Diary

Sometimes it can be difficult to pinpoint the causes of stress. Keeping a stress diary involves making a note of times and places where feelings of stress arise over the course of a few weeks. By keeping track of the thoughts and feelings that occur at the time, as well as your response to the situation, you can more easily identify your personal stressors and gain useful insight into how you react to stress.

Having identified the main sources of stress in your life, it may be possible to take steps to remove or avoid some of them. Working towards acceptance of the things that you cannot control will leave you free to focus on areas where your efforts can make a positive difference.

Getting Organized

The feeling of being overwhelmed by an excessive workload is a common source of stress. Learning how to prioritize tasks and mange time effectively can help reduce stress and improve work-life balance. Many different organizational and time management strategies exist, but most of them share some common ground.

Making a list, keeping a log or otherwise determining exactly what you need to get done can help make things seem more manageable and also makes it easier to prioritize. Reviewing the list and deciding which tasks are of critical importance and which can reasonably be postponed, delegated or discarded may reduce your immediate workload and allow you to concentrate on tackling essential activities first. Some people also find it useful to create an action plan or to break each task down into smaller steps.

Planning ahead and allowing sufficient time to get things done as well as setting personal boundaries and learning how to say “no” to people can help prevent an unmanageable workload from building up in the future.

Give Positive Thinking a Chance

There is evidence to suggest that individuals who are generally optimistic not only tend to cope better in stressful situations but are less likely to experience ill health than those of a more pessimistic disposition. The mechanisms underlying this are largely unknown, but what is understood is that whilst some people may appear to be naturally optimistic, positive thinking is a skill that can be learned.

It is important to note that positive thinking does not equate to ignoring problems or difficult situations; rather, it encourages a more constructive approach to dealing with them. For those prone to negativity, a number of exercises exist that can help strengthen the habit of thinking positively.

Research indicates that individuals who spend time deliberately seeking out the positive aspects of a situation or event that has caused them distress are less likely to experience on-going negative feelings about the situation or those involved than individuals who dwell on its frustrating or upsetting aspects. Taking time to consider the benefits that have arisen as a result of a difficult experience can reduce anger and frustration and foster feelings of hopefulness and positivity.

It has also been shown that individuals who complete the simple exercise of listing three things they are grateful for or that have gone particularly well over the preceding week can significantly increase their overall level of happiness for up to a month, promoting optimism and physical wellbeing.

Social Networks and Finding Support to Manage Stress

Strong social support networks are associated with improved psychological wellbeing and spending time in the company of supportive friends and family can have a positive impact upon stress. Willingness to ask for and accept help from others is a valuable skill, and the support received can be practical, such as provision of financial assistance, childcare or help with a specific task, or emotional: Talking things through with others can often help to keep things in perspective and spending time socializing can be a valuable source of comfort and emotional security, as well as providing respite from ongoing sources of stress. Conversely, spending time with people who are overly critical, negative or pessimistic can have the opposite effect, and research indicates that even those with strong social support can experience negative psychological consequences if they lack a sense of belonging.

Support need not come from existing friends or family members, and it can sometimes be beneficial to connect with others who have direct experience with a particular situation. Joining a support group can help reduce feelings of isolation or loneliness as well as providing access to information and practical advice. If you are struggling to cope with a stress then you can also seek help from your doctor or other healthcare professional.

Physical Exercise Can Help Stress

Regular exercise can benefit the mind and body, and has proven efficacy in the treatment of anxiety and depression in addition to supporting weight loss and reducing the risk of cardiovascular disease, diabetes, osteoarthritis and dementia.

Exercise is thought to alleviate stress by reducing levels of adrenaline and cortisol, whilst simultaneously stimulating production of chemical messengers called endorphins that promote feelings of happiness and wellbeing. Additionally, taking part in physical activity can provide a valuable opportunity to shift mental focus away from sources of stress and can also help to boost confidence and self-esteem.

Almost any form of exercise can be beneficial in terms of stress management, but choosing an activity that you enjoy and can build into your regular routine will make it easier to stay motivated. If you are not used to taking regular exercise then begin with lower impact activities and gradually increase the intensity as your fitness levels improve. Low impact does not mean ineffective: moderate forms of exercise such as walking can offer significant health benefits if performed regularly.

Both yoga and tai chi, which incorporate deep breathing and relaxation with low impact movement, have been shown to reduce stress and improve balance and flexibility. Many different styles of yoga and tai chi exist, to suit all ages and levels of fitness.

Consider Trying a Simple Relaxation Technique

Relaxation techniques can have a direct impact upon the physiological effects of stress, reducing muscle tension, lowering blood pressure and reducing heart rate. Numerous techniques exist, most of which can be self-taught and performed alone, without the need for specific props or equipment. Two of the most well validated exercises are diaphragmatic breathing and progressive muscle relaxation:

Diaphragmatic Breathing

Diaphragmatic breathing is a simple breathing technique that can be performed seated or supine. A version of the technique is used widely in Yoga

 

It is fine to fall asleep after completing the exercise if convenient to do so. Otherwise, take some time to bring your awareness back to your surroundings and get up slowly to avoid orthostatic hypertension.

Progressive Muscle Relaxation.

Progressive muscle relaxation (PMR) was originally developed in the 1920’s and many different forms now exist. Some people find it helpful to have someone talk them through the exercise or listen to a recorded version but this is by no means essential. It is best performed in the supine position with eyes closed, but can also be performed in a seated position as described.

Some people find they can achieve a deeper state of relaxation by deliberately tensing each group of muscles for a few seconds before allowing them to relax and progressing to the next group. If adopting this approach, take care to only tense the muscles in the group you are focusing on and do not over-tense to the point of pain. This can also be combined with relaxing breathing: take a breath in, then release the tension on the subsequent outward breath.

As with the diaphragmatic breathing exercise, it is fine to fall asleep afterwards if convenient to do so. Otherwise, gradually return your awareness to the room before opening your eyes. Take a few natural breaths then slowly get up.

  • Sit or lie down in a quiet place where your head is completely supported and you can fully relax. Loosen any restrictive clothing and aim to be as comfortable as possible.
  • If seated, place your arms on the arms of your chair with palms facing up, or allow your hands to rest gently in your lap, with palms upwards and fingers naturally uncurled. Keep your legs uncrossed. If lying down, place your arms a small distance from your body, with palms facing up and stretch out your legs, keeping your feet at least hip width apart.
  • Take a deep, slow, unforced breath in through your nose and allow your lungs to completely fill with air. Breathe out slowly through your mouth.
  • Breathe in slowly again, this time counting up to five in your head as you do so. If you are unable to maintain the inward breath in an unforced manner for a count of five at first, don’t worry. Just do as much as you are able.
  • Release the breath slowly, counting to five (or as much as you can manage comfortably without forcing the breath). Allow your breathing to flow naturally, without holding your breath or pausing during or between breaths.
  • There is no time limit to the exercise, just keep breathing in the manner described until you start to feel more relaxed or for as long as you are comfortable doing so. Aim to repeat once or twice per day, or as needed.
    • Start by taking a few deep, slow, unforced breaths in and out.
    • Turn your attention to your toes. Observe how they feel and take your time to consciously allow each toe to fully relax. Now focus on the rest of each foot, feeling its weight and allowing it to sink down into the bed. Gradually progress upwards to your ankles and then to your calves, paying attention to how each one feels and allowing it to relax completely and sink down into the bed before moving on.
    • Continue to relax your whole body in this manner, slowly working upwards to consciously relax the knees, thighs, hips, buttocks, abdomen and then the chest. When you reach your chest, pay attention to your breathing and deepen it, being aware of each breath and the rise and fall of your chest and abdomen.
    • Move your attention to your hands, sensing their weight and allowing them to relax down into the bed. When they are fully relaxed, progress to your wrists, lower arms, upper arms, shoulders, neck and then head.
    • When you reach your head, focus on your mouth, unclenching your jaw if necessary and allowing jaw and tongue to comfortably and completely relax. Observe how your eyes feel and let go of any tension in your eyelids. Consciously relax your cheeks, eyebrows and forehead.
    • When you have progressively relaxed your whole body in this manner, return your attention to your toes, moving on through your feet and upwards through the rest of your body to check if any areas of tension remain. Give focus to any areas of remaining tension, allowing them to fully relax.
    • If you struggle to maintain concentration throughout the exercise, don’t worry. Just return your attention to the last area you worked on and start over. Alternatively, take some time out to concentrate on your breathing before returning to the exercise when you feel ready.
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