Chapter 78: Weight gain

Obesity is the most common nutrition-related disorder in the Western world; as Tunnessen puts it, ‘Obesity is the most common form of malnutrition in the United States’.¹ Most overweight adults and children who are obese have exogenous obesity, which tends to imply that ‘they ate too much’, but the problem is more complex than relative food input. Physical activity and environmental and genetic influences must also be taken into account. However, only a small percentage (4–6%) of human obesity is thought to be due to a single gene mutation.² There is still a persisting tendency of affected families to blame ‘glandular’ problems as a cause of obesity. It is now considered that there is a strong genetic basis to obesity and that attributing it to overeating and lack of exercise is an overly simplistic viewpoint.

A summary of the diagnostic strategy model is presented in TABLE 78.1.

Probability diagnosis

The outstanding cause of weight gain in exogenous obesity is excessive calorie intake coupled with lack of exercise. This is determined largely by environmental influences. Overweight people often deny overeating but the true situation can be determined by recording actual food intake and energy expenditure, and by interviewing reliable witnesses.

Serious causes not to be missed

It is important not to misdiagnose hypothalamic disorders, which may result in hyperphagia and obesity. Injury to the hypothalamus may occur following trauma and encephalitis and with a variety of tumours, including craniopharyngiomas, optic gliomas and pituitary neoplasms. Some of these tumours may cause headaches and visual disturbances.

It is also important not to overlook major organ failure and kidney disorders as a cause of increased body weight, especially cardiac failure, liver failure and the nephrotic syndrome. The associated increase in body water needs to be distinguished from increased body fat. Consider the obesity hypoventilation syndrome (Pickwickian syndrome) in Grade III obese patients.

Pitfalls

Endocrine disorders

The endocrine disorders that cause obesity include Cushing syndrome, hypothyroidism, insulin-secreting tumours and hypogonadism. They should not represent difficult diagnostic problems.

An insulin-secreting tumour (insulinoma) is a very rare adenoma of the B cells of the islets of Langerhans. The main features are symptoms of hypoglycaemia and obesity.

Congenital disorders

The rare congenital disorders that cause obesity, such as Prader–Willi and Laurence–Moon–Biedl syndromes, should be easy to recognise in children (see CHAPTER 18 and later in this chapter).

Chromosomal abnormalities

An important abnormality to bear in mind is Klinefelter syndrome (XXY karyotype), which affects one out of every 400–500 males. The boys show excessive growth of long bones and are tall and slim. Without testosterone treatment they become obese as adults.

Some girls with Turner syndrome (XO karyotype) may be short and overweight.

Some gender pointers

Consider polycystic ovarian syndrome in women and obstructive sleep apnoea in obese men.

Seven masquerades checklist

The important masquerades include hypothyroidism and drug ingestion. Hypothyroidism is usually not associated with marked obesity. Drugs that can be an important contributing factor include tricyclic antidepressants, mirtazapine, corticosteroids, pizotifen, thioridazine, haloperidol, Depo-Provera and the contraceptive pill. Obesity (overeating) may be a feature of depression, especially in the early stages. Prescribed tricyclic antidepressants may compound the problem.

Psychogenic considerations

An underlying emotional crisis may be the reason for the overweight patient to seek medical advice. It is important to explore diplomatically any hidden agenda and help the patient to resolve any conflict.

A careful history is very valuable in ascertaining food and beverage intake and perhaps giving patients insight into their calorie intake, since some deny overeating or will underestimate their food intake.⁴ Enquire about gynaecological and family history, e.g. diabetes, cardiac disease.

Relevant questions

• Do you feel that you have an excessive appetite?

• Tell me in detail what you ate yesterday.

• Give me an outline of a typical daily meal.

• Tell me about snacks, soft drink and alcohol that you have.

• What exercise do you get?

• Do you have any special problems, such as getting bored, tense and upset or depressed?

• What drugs are you taking?

Examination

In the physical examination it is very important to measure body weight and height and calculate the BMI, and assess the degree and distribution of body fat and the overall nutritional status. A person’s adiposity is more important than body weight.⁵ Record the blood pressure and test the urine with dipsticks. Keep in mind that a standard blood pressure cuff on a large arm may give falsely elevated values. Remember the rare possibilities of Cushing syndrome, acromegaly and hypothyroidism. Search for evidence of atherosclerosis and diabetes and for signs of alcohol abuse.

An extensive working up of the CNS is not indicated in obesity without the presence of suspicious symptoms such as visual difficulties.

Investigations

It is essential to perform two measurements:

• weight and height (to calculate BMI)

• waist circumference

Important investigations

• Cholesterol/triglycerides

• Glucose (fasting)

• Liver function tests

• Electrolytes and urea

Investigations to consider

• Thyroid function tests

• Cortisol (if hypertensive)

• Testosterone (suspected sleep apnoea)

• ECG and chest X-ray (older than 40)

Anthropometric measurements⁵

Useful measuring instruments include:

• BMI: ‘healthy’ range is between 20 and 25

• Waist circumference: increased risk of comorbidities and is critical when considering cardiometabolic risk

  • – in men >94 cm (>102—high risk)

  • – in women >80 cm (>88—high risk)

    Measure waist halfway between inferior margin of last rib and crest of ilium in mid-axillary line over bare skin; use a stretch-resistant tape.

• Waist–hip circumference ratio (W/H ratio): healthy range <0.9—a better predictor of cardiovascular risk than BMI

• Single skinfold thickness (>25 mm suggests increased body fat)

• Upper arm circumference

• 4 skinfold thickness (sum of suprailiac, subscapular, triceps and biceps skinfolds)—for calculation of percentage body fat

Abdominal fatness, which is defined as a W/H ratio of >0.85 in women and >0.95 in men, is a more accurate indicator of the complications of diabetes. In practice, the combination of waist circumference and BMI is the most useful indicator of risk and relative change.⁵

Body mass index

The easiest and possibly most accurate assessment of obesity is the BMI (refer to Appendix V):

The RACGP recommends measuring the above two parameters every 2 years and recording them in the medical record.⁹

Garrow⁶ has produced a simple classification of the BMI associated with the relative degree of risk increase and suggested therapy (see TABLE 78.2).

The BMI has limitations. It doesn’t distinguish between men and women or between body types and it doesn’t work for children.

Various studies have found that approximately 10% of prepubertal and 15% of adolescent age groups are obese.¹

Obesity in children is a BMI for age >95th percentile while overweight is >85th percentile. There is a risk of obesity-associated diseases and carrying the problem into adulthood, with a greater risk of obesity, premature death and disability.

Childhood obesity is rising at an alarming rate worldwide—the figure is reportedly ten times higher than it was in 1970. The WHO reported that over 340 million children and adolescents aged 5–19 years were overweight or obese in 2016, with almost half of them living in Asia (WHO MONICA project).

Raising the issue with parents and child requires sensitivity and discretion. Parents often blame obesity in children on their ‘glands’, but endocrine or metabolic causes are rare and can be readily differentiated from exogenous obesity by a simple physical examination and an assessment of linear growth. Children with exogenous obesity tend to have an accelerated linear growth whereas children with secondary causes are usually short.

Congenital or inherited disorders associated with obesity

Prader–Willi syndrome

The characteristic features are bizarre eating habits (e.g. binge eating), obesity, hypotonia, hypogonadism, intellectual disability, small hands and feet and a characteristic facial appearance (narrow bifrontal diameter, ‘almond-shaped’ eyes and a ‘tented’ upper lip). Progressive obesity results from excessive intake in addition to decreased caloric requirements (see CHAPTER 18).

Laurence–Moon–Biedl syndrome

The characteristic features are obesity, intellectual disability, polydactyly and syndactyly, retinitis pigmentosa and hypogonadism.

Beckwith–Wiedemann syndrome

Characteristics include excessive growth, macrosomia, macroglossia, umbilical hernia and neonatal hypoglycaemia. Children appear obese as they are above the 95th percentile by 18 months of age. Intelligence is usually in the normal range.

Endocrine disorders

Endocrine disorders in children that can rarely cause obesity include hypothyroidism (often blamed as the cause but seldom is), Cushing syndrome, insulinomas, hypothalamic lesions, Fröhlich syndrome (adiposogenital dystrophy) and Stein–Leventhal syndrome (PCOS) in girls.

Managing obesity in children

Childhood obesity usually reflects an underlying problem in the family system. It can be a very difficult emotional problem in adolescents, who develop a poor body image. An important strategy is to meet with family members, determine whether they perceive the child’s obesity as a problem and whether they are prepared to solve the problem. The family dynamics will have to be assessed and strategies outlined. This may involve referral for expert counselling. It is worth pointing out that children eat between one-third and two-thirds of their meals at school so schools should be approached to promote special programs for children who need weight reduction.

Conventional therapy by dietary modification, increasing energy expenditure by increasing activity, reducing sedentary behaviour, behaviour modification and family involvement is recommended. The best outcomes are achieved with a specialist team working with the whole family.⁵ Some authorities emphasise that weight maintenance rather than weight loss is appropriate since many children will ‘grow into their weight’.⁷

Cushing syndrome

Cushing syndrome is the term used to describe the chemical features of increased free circulating glucocorticoid. The most common cause is iatrogenic with the prescribing of synthetic corticosteroids. The spontaneous primary forms such as Cushing disease (pituitary dependent hyperadrenalism) are rare. As the disorder progresses the body contour tends to assume the often quoted configuration of a lemon with matchsticks (see CHAPTER 23).

Clinical features

• Change in appearance

• Central weight gain (truncal obesity)

• Hair growth and acne in females

• Muscle weakness

• Amenorrhoea/oligomenorrhoea (females)

• Thin skin/spontaneous bruising

• Polymyalgia/polydipsia (diabetes mellitus)

• Insomnia

• Depression

Signs

• Moon face

• ‘Buffalo hump’

• Purple striae

• Large trunk and thin limbs: the ‘lemon with matchsticks’ sign

The patient should be referred for diagnostic evaluation, including plasma cortisol and overnight dexamethasone suppression tests.

Untreated Cushing syndrome has a very poor prognosis, with premature death from myocardial infarction, cardiac failure and infection; hence early diagnosis and referral is essential.

Obesity

Obesity and overweight are the most common pathological conditions in our society, creating on increasing public health problem. Worldwide in 2016, 39% of adults aged 18 years and over were overweight (39% of men and 40% of women) and 13% were obese (11% of men and 15% of women). Caused by an accumulation of adipose tissue, the problem is described as a ‘global health epidemic’ and also as a chronic disease (see TABLE 78.3). Each year, more than a million adults die due to conditions associated with obesity. It is not the extra weight per se that causes problems, but the excess fat. Calculating the BMI gives a better estimate of adiposity, and it is convenient and preferable to use this index when assessing the overweight and obese. However, recent data suggest that the distribution of body fat is as important a risk factor as its total amount. Abdominal fat (upper body segment obesity, or ‘apple’ obesity) is considered a greater health hazard than fat in the thighs and buttocks (lower body segment obesity, or ‘pear’ obesity) (see FIG. 78.1).

Obese patients with high waist–hip ratios (>1.0 in men and >0.9 in women) have a significantly greater risk of diabetes mellitus, stroke, coronary artery disease and early death than equally obese people with lower waist–hip ratios.²

In regard to the BMI reference scale it is worth noting that the risks follow a J-shaped curve (see FIG. 78.2) and are only slightly increased in the overweight range but increase with obesity so that a BMI of >40 carries a threefold increase in mortality.

The consequences of obesity include:

• cardiovascular:

  • – increased mortality (stroke, ischaemic heart disease, etc.)

  • – hypertension^*

  • – varicose veins

• metabolic:

  • – dyslipidaemia^*

  • – type 2 diabetes^*

  • – insulin resistance

  • – hyperuricaemia/gout

  • – infertility

  • – PCOS

• mechanical:

  • – osteoarthritis

  • – obstructive sleep apnoea^*

  • – restrictive pulmonary disease

  • – spinal dysfunction

  • – low back pain

  • – urinary incontinence

• other:

  • – hiatus hernia/GORD

  • – gall bladder disease^*

  • – fatty liver

  • – cancer (various)

  • – kidney disease (check microalbuminuria)

  • – excessive daytime sleepiness

  • – erectile dysfunction/subfertility

  • – psychological problems/depression/anxiety

Obesity is responsible for 80% of type 2 diabetes, 35% of ischaemic heart disease and 55% of hypertension in European adults.

Management

An imperative of treatment is to address the serious comorbidities of type 2 diabetes and insulin resistance. Lifestyle changes are fundamental to outcomes.

Treatment is based on four major interventions, the choice of which depends on the degree of obesity, the associated health problems and the health risk posed. Both the WHO and the NHMRC recommend the approach to obesity and overweight being based on these lifestyle changes, but with an emphasis on realistic goals.

1. reduction in energy (calorie) intake

2. change in diet composition including reduced fat intake

3. increased physical activity

4. behavioural therapy

Pharmacological agents are not used for first-line therapy although they may have a place in management, especially at grade III level of obesity. Surgery is an option for the treatment of morbid obesity.

There is no single effective method for the treatment of obesity, which is a difficult and frustrating problem. A continuing close therapist/patient contact has a better chance of success than any single treatment regimen.

1. no further weight gain

2. loss of 5–10% initial body weight

3. improve activity

Most successful programs involve a multidisciplinary approach to weight loss, embracing the four major interventions. The first goal should be no further weight gain. Emphasis must be on maintenance of weight loss. Behaviour modification is important and the most valuable strategy is to emphasise planning and record keeping with a continuous weekly diary of menus, exercise and actual behaviour.

Social support is essential for a successful weight loss program. A better result is likely if close family members, especially the chief cook, are involved in the program, preferably striving for the same goals.²

A close therapeutic supportive relationship with a patient can be effective using the following methods:⁸

1. Promote realistic goals. Lose weight at the same rate that it was gained (i.e. slowly)—for example, 5–10 kg a year. A graph can be used for this purpose with an ‘exaggerated’ scale on the vertical axis so that small variations appear highly significant and encouraging (see FIG. 78.3).

   • Promote the equation:

   • Energy In = Energy Out + Energy Stored

   • The appropriate way to reduce the stored energy (fat) is either to reduce energy in (eat less) or increase energy out (exercise).

2. Dietary advice. It is important to be realistic and allow patients to eat their normal foods but advise them about quantity and frequency. Give advice on simple substitutions (e.g. fortified skim milk in place of whole milk, high-fibre wholemeal bread instead of white bread, and fruit and vegetables instead of biscuits and cakes as in-between snacks).⁸ Reduce fat intake to <30% of total calorie intake.⁷ A strategy that seems to work effectively is to advise patients, especially those who are overweight (and grade I obesity), to eat one-third less than they usually do and discipline themselves not to ‘pick’ and to avoid second helpings.

3. Counselling is simple and commonsense. It involves being supportive, interested and encouraging. A list of tips on coping is provided (see below ‘A practical plan’ for grade II and III obesity) and the patient advised to keep a food, exercise and behaviour diary.

4. Review. ‘Review is the most vital part of the weight loss programme as it stimulates and revitalises motivation and enables assessment of progress.’⁸ It should be frequent initially (e.g. fortnightly), then monthly until the goal weight has been achieved and then 3-monthly. It is important never to be judgmental or critical if progress is unsatisfactory.

A practical plan

The following patient education sheet to be handed to patients represents useful advice to offer the obese patient.⁸ The emphasis is on a healthy lifestyle program.

• A brisk walk for at least 20–30 minutes each day is the most practical exercise.

• Other activities such as tennis, swimming, golf and cycling are a bonus.

Provide patients with a glycaemic index guide (see CHAPTER 10).

Breakfast:

• oatmeal (soaked overnight in water); after cooking, add fresh or dried fruit; serve with fat-reduced milk or yoghurt

  or

• muesli (homemade or from a health food store)—medium serve with fat-reduced milk, perhaps add extra fruit (fresh or dried)

• slice of wholemeal toast with a thin scraping of margarine, spread with Vegemite, Marmite or sugar-free marmalade

• fresh orange juice or herbal tea or black tea/coffee

Morning and afternoon tea:

• piece of fruit or vegetable (e.g. carrot or celery)

• freshly squeezed juice or chilled water with fresh lemon

Midday meal:

• salad sandwich with wholemeal or multigrain bread and thin scraping of margarine (for variety use egg, salmon, chicken or cheese fillings)

• drink as for breakfast

Evening meal:

• Summer (cold)—lean meat cuts (grilled, hot or cold), poultry (skin removed) or fish; fresh garden salad; slices of fresh fruit

• Winter (hot)—lean meat cuts (grilled), poultry (skin removed) or fish; plenty of green, red and yellow vegetables and small potato; fruit for sweets

• Have sensible goals; do not ‘crash’ diet but have a 6–12 month plan to achieve your ideal weight.

• Go for natural foods; avoid junk foods.

• Select fish, poultry and lean meats.

• Trim excess fat from meat and skin from poultry.

• Eat more breads (wholemeal), cereals, fruit and vegetables.

• Increase intake of complex carbohydrates that contain starch and fibre.

• Plant food is good for you; have it as part of breakfast.

• Eat less sugar; avoid lollies and syrups.

• Avoid alcohol, sugary soft drinks and high-calorie fruit juices.

• Strict dieting without exercise fails.

• If you are mildly overweight, eat one-third less than you usually do.

• Do not eat biscuits, cakes, buns, etc. between meals (preferably at no time).

• Limit the intake of full-cream products, fried foods and fatty take-away meals.

• Limit the amount of butter or margarine on vegetables and bread.

• Reduce calorie intake; reduce fat intake to <30% of total calorie intake.

• What you usually eat matters most, not what you eat occasionally.

• Use high-fibre foods to munch on.

• Drink copious water—at least 2 L a day.

• A small treat once a week may add variety.

• Avoid seconds and do not eat leftovers.

• Avoid non-hungry eating.

• Eat slowly—spin out your meal.

Pharmacological agents

A variety of these adjuvant agents are available or imminent but they have limitations and need to be used with caution, if at all. Adverse effects can be problematic. Consider for those with a BMI >30 kg/m² and failed well-supervised lifestyle measures.

The agents are:^4,5,9,10

• Local, acting on GIT:

  • — bulking agents (e.g. methylcellulose)

  • — lipase inhibitor—orlistat (Xenical) 120 mg (o) tds ac (used with a low-fat eating program)

• Centrally acting agents:

  • — amphetamine derivatives (reduce hunger): phentermine 15–40 mg (o) daily (limited use and not recommended)

  • — serotonin analogues (enhance satiety): fluoxetine 20–40 mg (o) daily in depressed patients but only temporary weight reduction⁷

  • — other SSRIs, e.g. sertraline

  • — sibutramine 10–15 mg (o) daily (monitor BP)

A summary of systemic reviews to date indicates that the effectiveness of serotonin analogues is unknown or, with sibutramine and phentermine, of some benefit, which has to be weighed against adverse effects, including the potentially fatal serotonin syndrome. The same applies to orlistat, which, together with a low-fat eating program, does produce extra weight loss over placebo.¹¹ Drugs should not be expected to have a continuing effect after therapy ceases.

Inappropriate drug treatment includes bulk-forming laxatives, thyroxine, diuretics, complementary and alternative medicines (which may cause adverse cardiovascular effects).⁷

Food replacement agents such as Optifast have been promoted but there is insufficient evidence so far to evaluate their effectiveness and the reduced intake of key vitamins. Long-term results are disappointing.

Surgery (bariatric surgery)^5,7

Surgery is the most effective treatment for obesity, but is associated with risks such as malabsorption⁴ and nutritional deficiency.¹² In those with morbid obesity (about 2% of the population) unresponsive to behaviour modification therapy and a course of pharmacological agents for 3 months or so, gastric banding has a place. It is recommended in those with a BMI >40 or >35 with at least one severe comorbidity such as poorly controlled diabetes or severe OSA.^13,14 One example is Lap-Band, which is inserted laparoscopically and can be adjusted and eventually removed with minimal significant residual adverse defect left in the stomach. It appears to be effective for 10 years.^5,14 Sleeve gastrectomy gastric bypass such as Roux-en-Y bypass and other techniques can be considered.

Oedema (dropsy) is an excessive accumulation of fluid in tissue spaces. It may be generalised or localised—periorbital, peripheral or an arm (lymphoedema, refer CHAPTER 69).

Generalised oedema

The site of generalised oedema is largely determined by gravity. It is due to an abnormal excess of sodium in the body, which leads to accumulation of water. The causes can be generally divided into two groups—oedema associated with a decreased plasma volume and oedema associated with an increased plasma volume (see TABLE 78.4).

Diagnosis

Clinical examination, including urinalysis, is usually sufficient to establish the cause of the oedema. In other cases, investigation of kidney or liver function may be required.

Treatment

• Treat the cause where known

• Salt (sodium) restriction

• Diuretics:

  • — a loop diuretic (e.g. frusemide)

  • — a potassium-sparing diuretic (e.g. spironolactone)

Idiopathic oedema

Idiopathic oedema, also known as cyclical or periodic oedema, is a common problem and the diagnosis is made on a characteristic history:

• exclusive to women

• may be cyclical or persistent

• usually unrelated to menstrual cycle

• excessive diurnal weight gain (worse on prolonged standing)

• abdominal bloating

• may affect hands and face as well as feet

• often made worse by diuretics

• may be associated with headache, depression, tension

Treatment of this condition is difficult. Most diuretics can aggravate the problem. Supportive stockings and a nutritious diet (with restricted sodium intake) are recommended as first-line treatment. A trial of spironolactone is often recommended.

Swelling (puffiness) of the face and eyelids

The causes are similar to those for generalised oedema. Important specific causes to consider are:

• kidney disease (e.g. nephrotic syndrome, acute nephritis)

• hypothyroidism

• Cushing syndrome and corticosteroid treatment

• mediastinal obstruction/superior vena cava syndrome

• angio-oedema

• skin sensitivity (e.g. drugs, cosmetics, hair dryers)

• carotico-cavernous fistula

Swelling of the legs

Refer to CHAPTER 69.

‘Cellulite’

‘Cellulite’ refers to a characteristic form of dimpling seen in the subcutaneous tissues of hips, buttocks and thighs of females. The dimpling pattern is related to the manner of attachment of fibrous septae that contain the fat. Many patients seek advice about ‘cellulite’ in the buttocks and thighs in particular. Explain that the best way to overcome it is to maintain an ideal weight. If overweight, lose it slowly and exercise to improve the muscle tone in the buttocks and thighs.

• Patients with grade II or III obesity (BMI >35) who are resistant to simple weight control measures.⁵

• Patients with associated medical problems such as angina or severe osteoarthritis who require relatively rapid weight reduction.

• Possibility of endocrine cause of obesity.

• Suspicion of congenital or inherited disorder in children.

Hand-out sheets from Murtagh’s Patient Education 7th edition:

• Obesity: how to lose weight wisely

• BMI calculator

NHMRC Obesity Guidelines. <www.health.gov.au/internet/main/publishing.nsf/Content/obesityguidelines-index.htm>.

RACGP Red book: the 5 As approach. <www.racgp.org.au/your-practice/guidelines/snap/2-approach-to-preventive-care-in-general-practice/21-the-5as/>.

WHO MONICA project. MONICA Monograph & Multimedia Sourcebook. Geneva: WHO, 2003.