Preliminary reportDiet-induced thermogenesis: variations among three isocaloric meal-replacement shakes
Introduction
Diet-induced thermogenesis (DIT), the increase in energy expenditure associated with the consumption of a meal, accounts for approximately 10% of an individual’s total daily energy expenditure [1]. The degree to which metabolism increases after a meal is strongly related to the energy content and macronutrient composition of the meal; e.g., the greater the energy content, the greater the DIT [2], [3], [4]. In terms of macronutrient content alone, DIT can increase by 6% to 8% for carbohydrate, 25% to 40% for protein, and 3% for fat [2], [3], [4]. In a study involving three isocaloric meals and two snacks controlled for taste, smell, and appearance over a 24-h period, widely varied carbohydrate (CHO), protein (PRO), and fat (60% CHO, 10% fat, 30% PRO versus 30% CHO, 60% fat, 10% PRO) intakes resulted in DIT differences of as much as 28% [5].
Current concerns about overweight and obesity have led to the promotion of quick fixes by consumers and the weight-loss industry; fast, easy-to-prepare meal-replacement shakes are one example. The objective of this study was to determine whether the consumption of low-calorie (1047 kJ, or 250 kcal), liquid meal-replacement shakes with wide variations in PRO, CHO, and fat content would result in variations in short-term DIT. If large variations in DIT were evident, then a particular shake type might offer an advantage over other shake types as a means of weight control.
Section snippets
Subjects
Three male subjects (29 ± 8.8 y, 175.7 ± 9.5 cm, 79.1 ± 9.6 kg) and five female subjects (28.6 ± 10.3 y, 163 ± 2 cm, 58.9 ± 4.8 kg) participated in the study (Table 1). All subjects were healthy, were not taking medications of any kind, and were physically active (i.e., engaging in activity at least three times per week for the previous 3 mo). We obtained informed consent from all subjects, and the institutional review board of the University of Southern Maine (Gorham, ME, USA) approved all
Results
Intraindividual measurements of the 10-min resting-and-reclining metabolic rate did not differ across the three trials (P = 0.77, standard error = 3.3 kJ). Group means also showed no differences in resting-and-reclining metabolic rate across trials (56.5 ± 5.9 kJ, 54 ± 10 kJ, and 55.7 ± 12 kJ, P = 0.91). DIT means were 136 ± 81 kJ for the All PRO shake, 209 ± 108 kJ for the Hi PRO Lo CHO shake, and 79 ± 48 kJ for the Lo PRO Hi CHO shake. A statistically significant difference in DIT over a 3-h
Discussion
Westerterp et al. [5] reported that extreme variations in fat and CHO content (60% CHO, 10% fat, 30% PRO versus 30% CHO, 60% fat, 10% PRO) can affect DIT over a 24-h measurement period, and the addition of CHO to an amino acid solution has been suggested to have a synergistic effect on DIT in acutely ill patients [2]. In our investigation of healthy, active subjects consuming low-calorie, liquid meal-replacement shakes, a greater DIT resulted from consumption of Hi PRO Lo CHO shake, especially
Summary and conclusions
Holding all energy expenditure and energy intake conditions constant, the 3-h DIT difference of 130 kJ (31 kcal) between the Lo PRO Hi CHO and Hi PRO Lo CHO shakes suggests that about a 4-mo period would be required to lose 0.5 kg of body fat. The difference in DIT found between these two shakes, although statistically significant, thus represents only a small contribution to daily energy expenditure and appears to have minimal practical applications for weight-control management.
References (10)
The influence of nutrient administration on energy expenditure in man
Clin Nutr
(1986)- et al.
Meal size and frequencyeffect on the thermic effect of food
Am J Clin Nutr
(1991) - et al.
Circadian variation of diet-induced thermogenesis
Am J Clin Nutr
(1993) - et al.
Cellular energy utilization and molecular origin of standard metabolic rate in mammals
Physiol Rev
(1997) - et al.
Obesity and leannessbasic aspects