Table 7.13.1 Classification of body mass index (BMI) and risk of comorbidities in adults (WHO, 1998; WHO Expert Consultation, 2004) Classification BMI (kg/m 2 ) BMI (kg/ m 2 ) Asian origin Risk of comorbidities Underweight <18.5 <18.5 Low (but risk of other clinical problems increased) Normal range 18.5 24.9 18.5 22.9 Average Overweight 25.0 29.9 23 27.4 Increased risk Obese class I 30.0 34.9 27.5 32.4 Moderate Obese class II 35.0 39.9 32.5 37.4 Severe Obese class III >40.0 >37.5 Morbid obesity Table 7.13.2 Waist measurements in adults as a predictor of health risk (WHO, 2008) Men Asian men Women Asian women Waist circumference (cm) Increased risk 94 80 Substantially increased risk Waist to hip ratio 102 90 88 80 Increased risk 0.9 0.85 Table 7.13.3 Healthy body fat ranges extrapolated from body mass index cut-offs in adults (Gallagher et al., 2000) African American (%) Asian (%) Caucasian (%) Underweight <20 <25 21 Healthy 20 32 25 35 21 33 Overweight 32 38 35 40 33 39 Obese >38 >40 >39 Manual of Dietetic Practice, Fifth Edition. Edited by Joan Gandy. 2014 The British Dietetic Association. Published 2014 by John Wiley & Sons, Ltd. Companion Website: www.manualofdieteticpractice.com
Table 7.13.4 Health risks of obesity (WHO, 1998) Greatly increased (relative risk >3)* Type 2 diabetes Gallbladder disease Dyslipidaemia Insulin resistance Breathlessness Sleep apnoea Metabolic Moderately increased (relative risk 2 3)* Cardiovascular diseases Hypertension Osteoarthritis (knees) Hyperuricaemia and gout Slightly increased (relative risk 1 2)* Certain cancers, including colon, kidney, prostate (men), postmenopausal breast and endometrial (women) Reproductive hormone abnormalities Polycystic ovary Impaired fertility Low back pain due to obesity Increased anaesthetic risk Foetal defects associated with maternal obesity *All relative risk estimates are approximate. Table 7.13.5 Evidence for factors that might promote or protect against overweight and weight gain (WHO/FAO, 2003b; Swinburn et al., 2005) Evidence Decreases risk No relationship Increases risk Convincing Probable Regular physical activity High dietary fibre/nsp intake Home and school environments that support healthy food choices for children Breastfeeding Possible Low glycaemic index foods Dietary protein content Insufficient Increased eating frequency Alcohol NSP, non-starch polysaccharide. Sedentary lifestyle High intake of energy dense foods Heavy marketing of energy dense foods and fast food outlets Adverse social and economic conditions (developed countries, especially for women) High sugar drinks Large portion sizes High proportion of food prepared outside the home (western countries) Rigid restraint/periodic disinhibition eating patterns
Table 7.13.6 Cost effectiveness results for selected interventions evaluated in Australia (source: Gortmaker 1991, p. 841. Reproduced with permission of Elsevier) Intervention type Target population (years) Strength of evidence* DALYs saved 10% unhealthy food and beverage tax (Sacks et al., 2011)** Adults 4 559 000 Front of pack traffic light nutritional labelling (Sacks et al., 2011)** Adults 5 45 100 Reduction of junk food advertising to children Children (0 14 years) 2 37 000 School based education programme to reduce television viewing Children (8 10 years) 3 8600 Multifaceted school based programme including nutrition and physical Children (6 years) 3 8000 activity School based education programme to reduce sugar sweetened drink Children (7 11 years) 3 5300 consumption Family based targeted programme for obese children Obese children (10 11 years) Multifaceted targeted school based programme Gastric banding adolescents (Ananthapavan et al., 2010) Family based GP mediated programme (Moodie et al., 2008) Gastric banding in adults** Overweight and obese children (7 10 years) Severely obese adolescents (14 19 years) Overweight/obese children (5 9 years) 1 2700 3 270 1 12300 3 510 Adults with a BMI over 1 140000 35 kg/m 2 *This classification (1 = strongest; 5 = weakest) is based on criteria adopted in ACE Prevention (Vos et al., 2010). 1 = sufficient evidence of effectiveness; 2 = likely to be effective; 3 = limited evidence of effectiveness; 4 = may be effective; 5 = inconclusive or inadequate evidence. **Interventions drawn from ACE-Prevention study (Vos et al., 2010). Interventions drawn from ACE-Obesity study (Carter et al., 2009). DALY, disability adjusted life years; BMI, body mass index. Table 7.13.7 Action levels for waist circumference Green zone (normal) Amber zone (action level 1)* Red zone (action level 2)** Women <80 cm <32 inches 80 87 cm 32 35 inches 88 cm 35 inches Men <94 cm <37 inches 94 101 cm 37 40 inches 102 cm 40 inches *Action level increasing health risks. **Action level 2 high health risks, seek advice to lose weight.
Table 7.13.8 Bariatric surgery procedures Procedure Mechanism of action Excess weight loss (%) Impact on nutrition Supplementation recommended Intragastric balloon Restrictive 10 Reduced intake supplement Adjustable gastric band (AGB) Sleeve gastrectomy Roux-en-Y gastric bypass (RYGB) Long limb gastric bypass Duodenal switch (biliopancreatic diversion with duodenal switch) (DS) Restrictive, no Restrictive, no Restrictive, possible Restrictive and malabsorptive, may experience steatorrhoea affecting absorption Restrictive and malabsorptive, steatorrhoea affecting absorption 50 Reduced intake 50 60 Reduced intake 65 68 Reduced intake Calcium, iron and vitamin B 12 absorption affected May experience dumping 65 68 Reduced intake Macronutrient possible Calcium, iron and vitamin B 12 absorption affected May experience dumping >70 Reduced intake Macronutrient possible Calcium, iron and vitamin B 12, fat soluble vitamin absorption affected supplement supplement. May also need calcium supplement, vitamin D and vitamin B 12 injections Protein (60 80 g/day) supplement, calcium supplement, vitamin D, vitamin B 12 injections Protein (60 80 g/day, may need 80 100 g/day if malabsorbing) supplement, calcium supplement, vitamin D and vitamin B 12 injections High protein (80 100 g/day), low fat diet supplement, high doses of fat soluble vitamins, calcium supplement, vitamin B 12 injections Table 7.13.9 Incidence of micronutrient deficiencies in bariatric surgery Vitamin mineral deficiency Presurgery Adjustable gastric band Sleeve gastrectomy Gastric bypass Biliopancreatic diversion ± duodenal switch Thiamine Uncommon Uncommon unless protracted vomiting occurs protracted vomiting occurs protracted vomiting occurs protracted vomiting occurs B 12 10 13% Uncommon Uncommon 12 33% Uncommon Folate Uncommon Uncommon Uncommon Uncommon Uncommon Iron 9 16% of adult women Uncommon May occur 20 49% May occur Vitamin A Uncommon Rare Rare Rare but may occur 50% at 1 year 70% at 4 years Vitamin D and calcium 60 70% (vitamin D) May occur May occur Common Increased risk of metabolic bone disease with low vitamin D, hypocalcaemia and secondary hyperparathyroidism Zinc Uncommon Uncommon Uncommon May occur Common Selenium Uncommon Uncommon Uncommon May occur Common Protein Uncommon May occur May occur May occur May occur Very common Increased risk of metabolic bone disease with low vitamin D, hypocalcaemia and secondary hyperparathyroidism A consensus statement for supplementation, gathered from a recent audit of good practice, will shortly be released by BOMSS (see BOMSS website for details).
Table 7.13.10 Brief description of behavioural change techniques (source: Stewart et al., 2008, table 2, p. 466. Reproduced with permission of Wiley-Blackwell Publishing) Goal setting Contracting Rewards for reaching goals Self monitoring Environmental/ stimulus control Problem solving Preventing relapse Goals for necessary changes in diet, physical activity levels and screen time are agreed between child, parent and dietitian. Goals should be SMART specific/small, measurable, achievable, recorded and timed The signing of a contract between the child, parent and dietitian establishes a commitment to achieving the goals in the allotted time period The parent agrees to give a reward to the child for achieving the agreed lifestyle change goals. This is a positive reinforcement for the setting and attainment of goals. The reward should be small, inexpensive and non-food or screen time. The parent should also be encouraged to use praise Recording targeted lifestyles, i.e. diet, physical activity and screen time. This enhances motivation by increasing self awareness of lifestyle behaviours and allows the child and parent to monitor progress towards set goals Encouraging changes in the environment to help to: Reduce the cues that encourage the behaviours requiring change, such as the parent not buying certain foods or the child not walking past a certain shop on the way home from school Promote new healthier behaviours or routines Helping the child and family to identify possible high risk situations that may make it difficult to stick to their goals, e.g. holidays, parties and wet weather, as well as identifying barriers to change and developing possible solutions to these barriers. This could be done as a paper exercise or as simulation and role play Near the end of the programme it is important to discuss and offer strategies to help avoid relapse into old behaviours. These include planning ahead for difficult situations and continuing with or returning to goal setting and self monitoring