Acute sodium ingestion has no effect on short-term food and water intake, subjective appetite, thirst, or glycemic response in healthy young men

Abstract

The high intake of dietary sodium (Na(+)) has been associated with obesity and insulin resistance, sparking the hypothesis that the consumption of salty foods affects food intake (FI) and postprandial blood glucose (BG) response. Therefore, we conducted 2 randomized repeated-measures experiments to examine the acute effects of the Na(+) content of solid food and beverage on FI, water intake (WI), subjective appetite, thirst, and BG. FI and WI were measured at ad libitum pizza test meals; appetite, thirst, and BG were measured at baseline and at regular intervals before and after meals. In the first experiment, 16 males (mean body mass index (BMI), 22.2 kg·m(-2)) consumed a low-Na(+) (71 mg) bean preload (300 kcal) with or without 740 mg or 1480 mg of added Na(+) 120 min prior to the pizza meal. Participants ate 116 kcal more at the test meal after consuming beans with 740 mg of added Na(+) than after beans with 1480 mg of added Na(+). In the second experiment, 19 males (mean BMI, 23.2 kg·m(-2)) consumed a low-Na(+) (62 mg) tomato beverage (73 kcal) with or without 500, 1000, 1500, or 2000 mg of added Na(+) 30 min prior to a pizza meal. The beverage with 2000 mg of added Na(+) led to higher WI during the pizza meal than the beverage with 500 mg of added Na(+). However, compared with the control conditions (no added Na(+)), added Na(+) treatments had no effect on dependent measures in either experiment. In conclusion, the acute intake of Na(+), in a solid or liquid form, did not affect short-term subjective ratings of appetite or thirst, ad libitum FI or WI, or BG in healthy young men.