Increased Hydration Can Be Associated with Weight Loss

Abstract

This mini-review develops the hypothesis that increased hydration leads to body weight loss, mainly through a decrease in feeding, and a loss of fat, through increased lipolysis. The publications cited come from animal, mainly rodent, studies where manipulations of the central and/or the peripheral renin–angiotensin system lead to an increased drinking response and a decrease in body weight. This hypothesis derives from a broader association between chronic hypohydration (extracellular dehydration) and raised levels of the hormone angiotensin II (AngII) associated with many chronic diseases, such as obesity, diabetes, cancer, and cardiovascular disease. Proposed mechanisms to explain these effects involve an increase in metabolism due to hydration expanding cell volume. The results of these animal studies often can be applied to the humans. Human studies are consistent with this hypothesis for weight loss and for reducing the risk factors in the development of obesity and type 2 diabetes.

Angiotensin-Converting Enzyme Ins/Del Polymorphism and Body Composition: The Intermediary Role of Hydration Status

“…Dehydration is particularly common within the youngest fraction of the population [1], and alarming evidences about the high prevalence of this problem emerge also from our population. Mild, but chronic, hypohydration is correlated with increased body weight and its attendant dysfunctions [33]. Two main hypotheses through which increased hydration can lead to body weight loss have been proposed: (1) a decrease in feeding, and (2) an increased lipolysis that consequentially induces a loss of fat [33].…”

“…Mild, but chronic, hypohydration is correlated with increased body weight and its attendant dysfunctions [33]. Two main hypotheses through which increased hydration can lead to body weight loss have been proposed: (1) a decrease in feeding, and (2) an increased lipolysis that consequentially induces a loss of fat [33]. The common denominator likely is the principal hormone of body fluid regulation, AngII.…”

Under What Conditions do Water-Intervention Studies Significantly Improve Child Body Weight?

“…Drinking water causes transient hypo-osmotic cell swelling, which activates osmosensitive neural pathways, which are hypothesized to drive thermogenesis [7,8] . In healthy, fasted individuals, hypo-osmotic cell swelling counteracts protein and glycogen breakdown in the liver, decreases blood glucose and insulin concentrations, and increases lipolysis and lipid oxidation [9] .…”

“…Drinking water favors fat oxidation by limiting exogenous carbohydrate and protein from beverages, by limiting endogenous glucose and amino acids from glycogen and protein breakdown, and by improving glucose clearance by reversing insulin insensitivity due to cell shrinkage and/or increasing energy expenditure [7][8][9] . Because some effects of drinking water on fat oxidation are mediated by lower blood glucose and insulin, the effects of drinking-water interventions on weight change may be magnified by a diet of low glycemic foods, and blunted by the intake of high glycemic food [19] .…”

Chronic water insufficiency induced kidney damage and energy dysregulation despite reduced food intake, which improved gut microbiota in female rats

“…The hypothesis was examined in male diet-induced obese Sprague-Dawley rats fed high-fat diets with limited water intake for 6 weeks. Water intake is recommended for weight loss to reduce hunger from less intake of food [15,16]. In NHANES 2009-2012, there is a significant association between inadequate hydration and elevated BMI in a cross-sectional study [15].…”