SWITCH: Weight Management Study
Research type
Research Study
Full title
SWITCH: EffectS of non-nutritive sWeetened beverages on appetITe during aCtive weigHt loss
IRAS ID
193868
Contact name
J.C.G Halford
Contact email
Sponsor organisation
University of Liverpool
Clinicaltrials.gov Identifier
Duration of Study in the UK
5 years, 11 months, 30 days
Research summary
Research Summary:
Non-nutritive sweeteners enable the production of sweet tasting but low calorie food and beverage products, which may help people reduce their energy intake whilst still consuming sweet flavours. In the long-term this may result in a reduction of body weight and risk of weight-related disease. Recent data from a range of short-term studies support the predicted reductions in energy intake. However, the effects of non-nutritive sweetened (NNS) beverages on long term weight management (both weight loss and weight maintenance) have not been assessed. To determine whether NNS beverages hinder or improve weight management efforts the present research will examine the impact of NNS beverages, as compared to water, on body weight, anthropometric measures, and body composition (in a subset) over the three study phases (12 weeks weight loss, 9 months active weight maintenance and an optional 12 months post active weight maintenance). Furthermore, the underlying mechanisms via which NNS may impact on weight management remain largely unexamined in humans. To determine if the effects of NNS on appetite are beneficial or detrimental to successful weight management, the study will also systematically compare the effects of NNS beverages, water and caloric beverages on appetite (hunger, satiety, liking and wanting) and energy intake (including food choice and caloric compensation) across the whole day during the three study phases in a further subset of participants.
Summary of Results:
The SWITCH trial aimed to compare the effects of non-nutritive sweetened (NNS) beverages and water on body weight during weight loss and maintenance in a behavioural weight management programme.
To achieve this aim, adults with a BMI of 27–35 kg/m2 who regularly consumed cold beverages were recruited and randomised equally between the two study arms (water or NNS beverages). Participants underwent a group behavioural weight management programme comprising weekly meetings during the initial 12-week weight-loss phase and monthly meetings during the 40-week assisted weight-maintenance phase. Weight maintenance was unassisted during the final 52-week phase. Participants were asked to consume two servings (each 330ml) per day of the intention-to-treat NNS beverage or water, which could be still or carbonated. Participants in the NNS group could also consume water. The primary endpoint was weight change at the end of each study phase. Secondary endpoints included changes in anthropometrics (waist and hip circumference), cardiometabolic risk factors (glycaemic control; fasting lipids; liver function), appetite and activity levels.
Four hundred and ninety three participants were randomised to the trial (water: n=246; NNS beverages: n=247). The 12-week timepoint was completed by 383 participants. At 12 weeks weight loss was equivalent with water versus NNS beverages. The 52-week timepoint was completed by 262 participants. At week 52 both groups had significant reductions in body weight from baseline but the groups were nonequivalent, with significantly greater weight loss in the NNS beverages group. However, this difference did not reflect clinical significance. The 104-week timepoint was completed by 220 participants. At 104 weeks weight loss remained significant and water and NNS beverages showed equivalence regarding weight change from baseline.
At all time points, waist and hip circumference were significantly reduced from baseline and significant improvements from baseline were observed for most biomarkers. There were no significant differences between groups for secondary end points except:
12 weeks:
reductions in waist circumference (greater with NNS beverages vs. water) reductions in glycated hemoglobin (greater with water vs. NNS beverages).52-weeks:
reductions in hip circumference (greater with NNS beverages vs. water) changes in HDL cholesterol (increased with NNS beverages)104 weeks:
increases in total cholesterol (greater with NNS beverages vs water) changes in glycated hemoglobin (increased with NNS beverages)Results suggest that both water and NNS beverages may aid weight loss and subsequent weight maintenance in people taking part in a behavioral weight-management program. Importantly, weight loss achieved at 12 weeks was maintained up to week 104. Both NNS beverages and water improved anthropometric and other outcomes over the 2 year period.
REC name
North West - Liverpool Central Research Ethics Committee
REC reference
16/NW/0347
Date of REC Opinion
28 Jun 2016
REC opinion
Further Information Favourable Opinion