Abstract

BACKGROUND:

Several studies show that proteins, including whey and casein, are more satiating than carbohydrates. It follows that skim milk would be more satiating than sugar-rich beverages. However, this has yet to be shown.

OBJECTIVE:

The objective was to investigate the effects of drinking skim milk in comparison with a fruit drink at breakfast on self-reported postmeal satiety and energy intake at lunch.

DESIGN:

In a randomized crossover trial, 34 overweight women (n = 21) and men (n = 13) attended 2 sessions 1 wk apart. At each session, participants consumed a fixed-energy breakfast together with either 600 mL skim milk (25 g protein, 36 g lactose, <1 g fat; 1062 kJ) or 600 mL fruit drink (<1 g protein, 63 g sugar, <1 g fat; approximately 1062 kJ). Participants provided satiety ratings throughout the morning. Four hours after breakfast they consumed an ad libitum lunch, and energy intake was assessed.

RESULTS:

Participants consumed significantly less energy at lunch after consuming skim milk (mean: 2432 kJ; 95% CI: 2160, 2704 kJ) than after consuming the fruit drink (mean: 2658 kJ; 95% CI: 2386, 2930 kJ), with a mean difference of approximately 8.5% (P < 0.05). In addition, self-reports of satiety were higher throughout the morning after consumption of skim milk than after consumption of the fruit drink (P < 0.05) with the differences becoming larger over the 4 h (P < 0.05).

CONCLUSION:

Consumption of skim milk, in comparison with a fruit drink, leads to increased perceptions of satiety and to decreased energy intake at a subsequent meal. This trial was registered with the Australian New Zealand Clinical Trials Registry at (www.anzctr.org.au) as ACTRN12608000510347.