Are noncaloric drinks better than sugar-sweetened ones?

Replacing sugar-sweetened beverages (SSBs) with noncaloric drinks such as artificially sweetened beverages (ASBs) or unsweetened beverages (USBs) did not affect the serum triglyceride-HDL-C ratio (TG:HDL-C) of adults who report regular SSB intake, a study has shown. However, doing so had a favourable impact on body weight and central adiposity, while USBs trumped the other two beverage types in terms of sweet taste preference.

The transition from SSB to noncaloric options has been driven by the growing awareness on the adverse health impact of increased sugar consumption. [Circulation 2017;135:e1017-e1034; Am J Clin Nutr 2013;98:1084-1102]

The team thus sought to determine if such transition will be beneficial in 203 adults (60 percent male) who reported habitual SSB intake (at least one serving [12 fl oz] per day). Participants were randomized 1:1:1 to consume home-delivered SSBs, ASBs, or USBs daily for 12 months. [J Am Heart Assoc 2020;doi:10.1161/JAHA.119.015668]

Cardiometabolic risk factors, adiposity

At 12 months, there were no significant differences between arms in terms of changes in TG:HDL-C (p=0.65), as well as insulin sensitivity (p=0.38), β-cell function (p=0.49), body weight (p=0.66), and fat mass (p=0.27).

“[These suggest that] replacing SSBs with ASBs or USBs had no effect on cardiometabolic risk factors,” said the researchers. Longer study periods may be warranted to ascertain the effects of substituting SSBs with noncaloric options on these variables, they added.

However, these findings may have been influenced by the reduced intake of refined grains among SSB consumers, leading to improvements in HEI* score (mean change, 0.80; p=0.05). “To detect the potential effects of beverage consumption on these variables … more attention may be needed toward behavioural strategies for controlling intake of other foods (most notably, sources of refined carbohydrate) that could attenuate the independent effects of beverage consumption in intervention studies,” they explained.

When participants were stratified according to baseline trunk fat, there were significant effect modifications across the three tertiles in terms of body weight (p=0.006) and fat mass (p=0.004). “As such, among individuals with central adiposity, replacing SSBs with either ASBs or USBs had a favourable effect on body weight and fat mass,” said the researchers.

USBs: Turning the sweet tide

In the USB arm, there was a significant reduction in both sweetness threshold (p=0.005) and favourite concentration (p<0.0001). Among those consuming ASBs, only favourite concentration dropped (p=0.02).

These imply that sweet taste preference dropped more when SSBs were substituted with USBs compared with ASBs. “[This suggests that] USBs were a better replacement than ASBs for decreasing sweet taste preference, particularly sweetness threshold, a finding with plausible implications for promoting adherence to prescribed low-sugar diets,” they added. These findings also support data highlighting the importance of USB intake. [http://health.gov/dietaryguidelines/2015/guidelines, accessed October 22, 2020]

SSBs: The downside

In participants with the greatest baseline trunk fat, SSB consumption led to greater weight gain vs ASB or USB intake (mean change, 4.4 kg vs 0.5 kg [ASB] or −0.2 kg [ASB]; p=0.002). This effect may be attributed to the increased daily SSB consumption by one serving (p<0.001).

“[The] consumption of high-glycaemic-load sources of carbohydrate such as SSBs may promote weight gain by raising the post-prandial ratio of serum insulin to glucagon, resulting in increased hunger and decreased energy expenditure,” explained the researchers. Moreover, given the free home delivery, SSB consumers tended to increase – instead of maintain – their levels of SSB intake, they added.

Also, neither sweetness threshold (p=0.40) nor favourite concentration (p=0.36) changed for those consuming SSBs, suggesting that increased exposure to SSBs does not influence sweet taste preference.

Overall, the current findings support the AHA** recommendations to substitute SSBs with either ASBs or USBs to help control body weight in susceptible individuals, such as those with central adiposity. [Circulation 2018;138:e126-e140] It is also important to take overall dietary quality into account when implementing SSB interventions to reduce cardiometabolic disease risk, noted the researchers.