Salt, soft drinks & obesity Dr. Feng He

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1 Salt, soft drinks & obesity Dr. Feng He Wolfson Institute of Preventive Medicine, Barts and The London School of Medicine & Dentistry, Queen Mary University of London, UK

2 BP Salt CVD Obesity Type 2 Diabetes

3 Salt Thirst Fluid intake (SSBs ) Food Calorie Obesity

4 Salt & fluid intake Experiment in rats Water intake (ml/day) Salt concentration in diet (%) Week Gamble et al. Am J Physiol 1929;88:571-80

5 Salt & fluid intake Metabolic study (Only salt intake was changed in 104 untreated hypertensives) 2.5 High Salt Low Salt Fluid intake (L/d) *** Salt intake (g/d) *** P<0.001 high salt vs low salt *** He et al. Hypertension 2001;38:317-20

6 Salt & fluid intake Metabolic study 2 1 Change in fluid intake (L/d) r = P< Change in salt intake (g/d) He et al. Hypertension 2001;38:317-20

7 Cross-sectional study - on usual salt intake (634 untreated hypertensives) 6 5 Fluid intake (L/d) r = 0.38 P< Salt intake (g/d) NB: The association remained significant after adjusting for age, sex, ethnic group, body weight, MAP, urinary potassium & creatinine. He et al. Hypertension 2001;38:317-20

8 Salt & fluid intake INTERSALT study 10,079 individuals from 52 centres around the world Significant association between salt & fluid intake in both hypertensives and normotensives (adjusted for age, sex, BMI, SBP, alcohol intake, urinary potassium, creatinine, magnesium & nitrogen) He et al. Hypertension 2001;38:317-20

9 Salt & fluid intake Comparison of 3 studies 0.05 Change in fluid intake (L/d) INTERSALT Hypertensives Normotensives Metabolic study Cross-sectional study Change in salt intake (g/d) Salt is an important determinant of fluid intake in adult population He et al. Hypertension 2001;38:317-20

10 Salt & fluid intake in adults 5 g/d salt intake (e.g g/d) 350 ml/d fluid intake Soft drinks proportionately He et al. Hypertension 2001;38:317-20

11 Salt, Fluid & SSBs in Children NDNS for young people (4-18 yr) in Great Britain (N=1688) Salt intake is significantly associated Total fluid intake SSBs 1 g/d salt intake 27 g/d SSBs Adjusted for age, sex, body weight and hours spent on moderate and vigorous physical activities He et al. Hypertension 2008;51:629-34

12 Salt & SSBs in children - UK 50% salt (i.e. 3 g/d) in all children (4-18 yrs) 2 cans of SSBs per week per child 1 billion SSBs per year He et al. Hypertension 2008;51:629-34

13 Salt & SSBs Other countries Significant association was reported in children & adolescents in Australia Grimes et al. Pediatrics. 2013;131: USA Grimes et al. Am J Clin Nutr. 2013;98:189-96

16 Soft drinks High in sugar Low satiation Incomplete compensation High GI Hunger, more calorie consumed Calorie intake Obesity

17 Soft drink consumption & obesity Prospective cohort study 548 children aged years, followed up for 19 month Each additional can of SSB daily 60% in obesity (P<0.05) (Adjusted for age, sex, ethnicity, baseline anthropometrics, energy intake, physical activity, time spent on watching TV & videos) Ludwig et al. Lancet 2001;357:505-8

18 Soft drinks & obesity Randomised trial 6 primary schools 644 children aged 7-11 yrs Intervention: Consumption of carbonated drinks Duration: 1 yr 1.5 carbonated soft drinks / week / child 7.7% in the number of overweight and obese children (P<0.05) James et al. BMJ 2004;328:

19 Salt & obesity Role of the industry

20 Salt Thirst Fluid intake (SSBs ) Food Calorie Obesity

21 Salt Thirst Fluid intake (SSBs ) Food Calorie Obesity

23 Salt & food consumption 48 adults, age yr Randomised cross-over design 4 lunchtime sessions after eating the same breakfast Meals: Pasta (56%), sauce (44%) 1) low-fat (0.02% fat)/low-salt (0.06% NaCl) 2) low-fat/high-salt (0.5% NaCl) 3) high-fat (34% fat)/low-salt 4) high-fat/high-salt Participants were told to eat as much as they like until comfortably full Bolhuis et al. J Nutr 2016 Online first

24 Salt food intake Lower salt Higher salt Low fat High fat Low fat High fat Food intake (g) Salt P<0.05 Fat P=0.60 Bolhuis et al. J Nutr 2016 Online first

25 Salt and Obesity Direct link

26 Salt intake & BMI / waist circumference adjusted for confounders including calorie intake (UK NDNS RP 2008/ /2012) Children (N=458) Adults (N=785) BMI (kg/m 2 ) BMI (kg/m 2 ) Salt intake tertile Lower M iddle Upper P<0.01 1st 2nd 3rd P<0.01 Waist 80 Circumference BMI Waist Circumference (cm) Waist Circumference (cm) Ma et al. Hypertension 2015;66:843-9

27 Salt intake & obesity (UK NDNS RP 2008/ /2012) 1 g/d Salt 20% obesity risk in both children & adults (adjusted for confounders including calorie intake or SSBs) Results were consistent Different measures of salt intake Different measures of adiposity Ma et al. Hypertension 2015;66:843-9

Salt intake & body fat (UK NDNS RP Doubly Labeled Water Sub-study) Children (N=67) Salt/energy ratio (g/2000kcal) Regression Coefficient P value body fat mass

28 Salt intake & body fat (UK NDNS RP Doubly Labeled Water Sub-study) Children (N=67) Salt/energy ratio (g/2000kcal) Regression Coefficient P value body fat mass (kg) 0.5 <0.05 body lean mass (kg) Adults (N=117) body fat mass (kg) 1.2 <0.01 body lean mass (kg) Ma et al. Hypertension 2015;66:843-9

29 Salt & obesity other countries (Australia, Denmark, Germany, Korea, Japan) Cross-sectional studies Salt intake obesity % body fat (independent of calorie intake or SSBs) Grimes et al. Br J Nutr. 2016;115: Libuda et al. Public Health Nutr. 2012;15: Lee et al. Br J Nutr. 2016;115: Murakami et al. Br J Nutr. 2015;113:

30 Prospective cohort study 215 adults Salt intake (24h UNa) measured at baseline Followed up for 6 yrs Salt associated with subsequent gain in body fat 6 g/d salt 0.24 kg body fat (P<0.05) (Adjusted for age, sex, education level, smoking, physical activity, alcohol consumption, menopausal status for women, height, baseline total energy intake, baseline body fat & change in body weight between baseline and follow-up. Larsen, et al. PLoS One. 2013;8:e69689

31 Potential mechanisms (from animal studies) Volume of visceral adipocyte Activity of enzymes in lipid synthesis Glucose incorporation into lipids Leptin level Fonseca-Alaniz MH, et al. Obesity. 2007;15: Dobrian, A.D, et al. Am J Physiol Renal Physiol, (4).

32 Summary Salt SSBs Directly Food Obesity

33 Conclusion Obesity Multifactorial Comprehensive strategy is needed, particularly calorie dense foods & drinks Salt intake Important part of the strategy to obesity

In adults, the quantitative relationship between salt intake

In adults, the quantitative relationship between salt intake Salt Intake, Hypertension, and Obesity in Children Salt Intake Is Related to Soft Drink Consumption in Children and Adolescents A Link to Obesity? Feng J. He, Naomi M. Marrero, Graham A. MacGregor Abstract