Sweet news about low- and zero-calorie beverages

Background

High consumption of sugar-sweetened beverages (SSBs) is strongly associated with an increased risk of obesity and cardiometabolic complications. Although many people use low-calorie (and zero-calorie) sweetened beverages (LCSBs) to replace SSBs, their use remains controversial.

The study

This network meta-analysis of randomized controlled trials assessed the effects of the following interventions on body weight and cardiometabolic risk factors:

• Substituting SSBs with LCSBs

• Substituting SSBs with water

• Substituting water with LCSBs

The inclusion criteria specified that the randomized controlled trials (RCTs) must be at least 2 weeks long and excluded studies that assessed sweeteners in nonbeverage form (e.g., tablets) or in fortified or nutrient-dense beverages (e.g., milk and juice). The included studies assessed participants both with and without diabetes.

The primary outcome was body weight. The authors also assessed the following secondary outcomes:

• BMI

• Body fat percentage

• Waist circumference

• HbA1C

• Fasting blood glucose

• 2-hour postprandial glucose during a 75-gram oral glucose tolerance test

• Fasting plasma insulin

• HOMA-IR

• LDL-C

• HDL-C

• Triglycerides

• Total cholesterol

• Non-HDL cholesterol

• Systolic blood pressure

• Diastolic blood pressure

• Liver fat

• Liver enzymes alanine aminotransferase and aspartate aminotransferase (ALT and AST)

• Uric acid

The authors assessed 17 RCTs with 24 trial comparisons, including 1,733 adults (75% women; average age of 33; median BMI of 31). The median follow-up period was 12 weeks, with studies ranging from 3 to 52 weeks in duration. Nine RCTs exclusively assessed participants with overweight or obesity, and 1 trial exclusively assessed patients with type 2 diabetes.

Eight RCTs (11 comparisons) reported the low-calorie or zero-calorie sweetener used: 7 comparisons used aspartame, and 1 comparison each assessed an aspartame and acesulfame potassium blend, saccharin, rebaudioside A, and sucralose.

LCSBs substituted for SSBs in 12 RCTs, water substituted for SSBs in 3 RCTs, and LCSBs substituted for water in 9 RCTs.

Eight RCTs were funded by agencies (government, not-for-profit agency, or university), 4 were funded by industry, and 5 were funded by a combination of agency and industry.

The results

Substituting SSBs with LCSBs reduced body weight (−1.06 kg), BMI (−0.32), body fat percentage (−0.6%), and liver fat. Substituting SSBs with water was not associated with any significant outcome (although the results tended to favor water for nearly all outcomes). Substituting water with LCSBs reduced body weight (−1.07 kg), increased HbA1C (+0.21%), and reduced systolic blood pressure (−2.63 mm Hg).

The certainty of evidence for body weight was moderate for substituting SSBs with LCSBs, low for substituting SSBs with water, and low for substituting water with LCSBs.

Note

The authors declared several conflicts of interest — they reported receiving support from companies such as Loblaws Companies Limited (a Canadian food distributor), the National Honey Board, the Canadian Sugar Institute, Ocean Spray, General Mills, the International Sweeteners Association, Danone, Unilever, Kelloggs, Pepsi-Co, Sun-Maid, and Nestlé.