Impact of water intake on energy intake and weight status: a systematic review

Abstract

The effects of consuming water with meals rather than drinking no beverage or various other beverages remain under-studied. This systematic review of studies reported in the English-language literature was performed to compare the effects of drinking water and various beverage alternatives on energy intake and/or weight status. Relevant clinical trials, epidemiologic studies, and intervention studies were identified and findings across the literature were summarized. From the clinical trials, average differences were calculated in total energy intake at test meals (DeltaTEI) for each of several beverage categories in comparison with water. The available literature for these comparisons is sparse and somewhat inconclusive. However, one of the most consistent sets of findings was related to adults drinking sugar-sweetened beverages (SSBs) versus water before a single meal. In these comparisons, total energy intakes were 7.8% higher (DeltaTEI range, -7.5 to 18.9) when SSBs were consumed. Studies comparing non-nutritive sweeteners with water were also relatively consistent and found no impact on energy intake among adults (DeltaTEI, -1.3; range, -9 to 13.8). Much less conclusive evidence was found in studies replacing water with milk and juice, with estimated increases in TEI of 14.9% (range, 10.9 to 23.9%). These findings from clinical trials, along with those from epidemiologic and intervention studies, suggest water has a potentially important role to play in reducing energy intake, and consequently in obesity prevention. A need for randomized-controlled trials to confirm this role exists.

Figure 1. Difference in total energy intake when drinking water is removed from a meal

Total energy intake (TEI) includes combined kcal from preload and test meal. Differences presented are %ΔTEI calculated as 100*(TEI(w/no water)−TEI(w/water)) / TEI(w/water). Weighted averages of ΔTEI across multiple studies were computed as ΔTEI_wa=∑(ΔTEI*N) ÷ ∑(N). All presented studies were included in weighted averages, regardless of significance.

Figure 2. Difference in total energy intake when juice or milk displace water

Total energy intake (TEI) includes combined kcal from preload and test meal. Differences presented are %ΔTEI calculated as 100*(TEI(w/beverage)−TEI(w/water)) / TEI(w/water). Weighted averages of ΔTEI across multiple studies were computed as ΔTEI_wa=∑(ΔTEI*N) ÷ ∑(N). All presented studies were included in weighted averages, regardless of significance.

Figure 3. Differences in total energy intake when HFCS or sucrose sweetened beverages displace water

Total energy intake (TEI) includes combined kcal from preload and test meal. Differences presented are %ΔTEI calculated as 100*(TEI(w/beverage)−TEI(w/water)) / TEI(w/water). Weighted averages of ΔTEI across multiple studies were computed as ΔTEI_wa=∑(ΔTEI*N) ÷ ∑(N). All presented studies were included in weighted averages, regardless of significance.

Figure 4. Differences in total energy intake when diet beverages displace water

Total energy intake (TEI) includes combined kcal from preload and test meal. Differences presented are %ΔTEI calculated as 100*(TEI(w/beverage)−TEI(w/water)) / TEI(w/water). Weighted averages of ΔTEI across multiple studies were computed as ΔTEI_wa=∑(ΔTEI*N) ÷ ∑(N). All presented studies were included in weighted averages, regardless of significance.