Table 4.

Intervention Studies on Hydration and Weight Management ¹.

Citation	Study Objective	Population	Design	Intervention	Summary/Conclusion
Wong et al., 2017 [86]	Compare a standard weight-loss program with and without water	38 overweight and obese adolescents who reported drinking ≤4 cups of water/d; Control: 6M/13F, mean age 15.7 y; Water: 5M/14F, mean age 14.1 y	6 month parallel RCT	All participants received similar weight-reducing interventions (i.e., dietary counseling, daily text messages, and a cookbook with health guides). Control: No specific advice on water consumption. +Water: Received well-defined water messages through counseling and daily text messages, a water bottle, and a water pitcher with filters, and a target to increase habitual water intake to 8 cups/d.	Water group consumed more water [4.8 (3.8 to 5.9) cups of water/d] compared to the Control group [3.5 (2.6 to 4.4) cups/d]. Changes in BMI z-score and other anthropometric measures did not differ significantly between the two groups.
Parretti et al., 2015 [85]	Investigate the efficacy of water preloading before meals as a weight loss strategy for adults with obesity.	84 obese adults; Control: 15/28 M/F, mean age 57.8 y; Water: 15/26 M/F, mean age 55.1 y	12 week parallel RCT	All participants were given a face-to-face weight management consultation at baseline and a follow-up telephone consultation at 2 weeks. Control: Instructed to imagine their stomach was full before meals. +Water: Instructed to drink 500 mL of water 30 min before their main meals.	Water group lost 1.3 kg more than control group at 12 weeks.
Corney et al., 2015 [84]	Examine the effects of hydration status and/or fluid availability during eating on ad libitum energy intake	16 healthy males, average age 25 y.	Acute RCT	Subjects provided standard foods for 24 h which were designed so subjects are euhydrated or hypohydrated. Ad libitum breakfast was provided the next day.	Hydration status prior to ad libitum breakfast did not affect energy intake. Those who were hypohydrated (~1.8% body mass loss) consumed more fluids during breakfast compared to those who were euhydrated.

Abbreviations: BMI, body mass index; d, day; F, female; h, hours; kg, kilograms; M, male; mL, milliliter; n, sample size; RCT, randomized clinical trial; y, years. ¹ Intervention trials published since January 2014 through April 2018; studies included in the 2018 Stookey review were not included in this table.