INTRODUCTION: Low-calorie sweetener use for weight control has come under increasing scrutiny as obesity, especially abdominal obesity, remain entrenched despite substantial low-calorie sweetener use. We evaluated whether chronic low-calorie sweetener use is a risk factor for abdominal obesity.
PARTICIPANTS AND METHODS: We used 8268 anthropometric measurements and 3096 food diary records with detailed information on low-calorie sweetener consumption in all food products, from 1454 participants (741 men, 713 women) in the Baltimore Longitudinal Study of Aging collected from 1984 to 2012 with median follow-up of 10 years (range: 0-28 years). At baseline, 785 were low-calorie sweetener non-users (51.7% men) and 669 participants were low-calorie sweetener users (50.1% men). Time-varying low-calorie sweetener use was operationalized as the proportion of visits since baseline at which low-calorie sweetener use was reported. We used marginal structural models to determine the association between baseline and time-varying low-calorie sweetener use with longitudinal outcomes-body mass index, waist circumference, obesity and abdominal obesity-with outcome status assessed at the visit following low-calorie sweetener ascertainment to minimize the potential for reverse causality. All models were adjusted for year of visit, age, sex, age by sex interaction, race, current smoking status, dietary intake (caffeine, fructose, protein, carbohydrate, and fat), physical activity, diabetes status, and Dietary Approaches to Stop Hypertension score as confounders.
RESULTS: With median follow-up of 10 years, low-calorie sweetener users had 0.80 kg/m2 higher body mass index (95% confidence interval [CI], 0.17-1.44), 2.6 cm larger waist circumference (95% CI, 0.71-4.39), 36.7% higher prevalence (prevalence ratio = 1.37; 95% CI, 1.10-1.69) and 53% higher incidence (hazard ratio = 1.53; 95% CI 1.10-2.12) of abdominal obesity than low-calorie sweetener non-users.
CONCLUSIONS: Low-calorie sweetener use is independently associated with heavier relative weight, a larger waist, and a higher prevalence and incidence of abdominal obesity suggesting that low-calorie sweetener use may not be an effective means of weight control.
As scientists recognise, observational studies, by their nature, cannot prove cause and effect. On this basis, Chia et al study findings supporting that older people who consume low calorie sweeteners had 0,8kg/ m2 higher BMI and larger waist circumference, compared to non-consumers, cannot provide evidence towards this relation.
Furthermore, with regards to the study methodology, the two groups are not comparable at baseline, as LCS users had already higher BMI and waist circumference when they were recruited for the study. A key point of this study is not only whether LCS users/ ever users are heavier at baseline (which is obvious and recognized), but whether subjects who gain weight tend to remain or become LCS users. This sort of reverse causation cannot be addressed in an observational study (particularly of such a small size, i.e. 785 LCS-users vs 669 non-users). On the contrary, human clinical trials do not support that low calorie sweeteners may cause weight gain. This is consistent with the fact that low calorie sweeteners have no calories to contribute to either gaining weight or developing fat. For more information please read the ISA comments by clicking here.