Diet order significantly affects energy balance for diets varying in macronutrients but not ultraprocessing in crossover studies without a washout period.
Am J Clin Nutr
; 2024 Aug 18.
Article
en En
| MEDLINE
| ID: mdl-39163976
ABSTRACT
BACKGROUND:
Crossover studies can induce order effects, especially when they lack a washout period.OBJECTIVES:
We performed secondary analyses comparing groups of subjects randomly assigned to different diet orders in 2 inpatient crossover studies originally designed to compare within-subject differences in ad libitum energy intake. One study compared minimally processed low-carbohydrate (LC) compared with low-fat (LF) diets, and the other matched macronutrients and compared minimally processed food (MPF) with ultraprocessed food (UPF) diets.METHODS:
Diet order group comparisons of changes in body weight and body composition, and differences in energy expenditure and food intake were assessed over 4 wk in 20 adults randomly assigned to either the LC followed immediately by the LF diet (LC â LF) or the opposite order (LF â LC), and 20 adults randomly assigned to either the MPF followed by the UPF (MPF â UPF) diets or the opposite order (UPF â MPF).RESULTS:
Subjects randomly assigned to LC â LF lost 2.9 ± 1.1 kg more body weight (P <0.001) and 1.5 ± 0.6 kg more body fat (P = 0.03) than the LF â LC group, likely because the LC â LF group consumed 921 ± 304 kcal/d less than the LF â LC group (P = 0.003). These energy intake differences were driven by the last 2 wk (-1610 ± 312 kcal/d; P < 0.0001), perhaps because of carryover effects of gut adaptations during the first 2 wk arising from large differences in the mass of food (1296 ± 215 g/d; P <0.00001) and fiber consumed (58 ± 6 g/d; P <0.00001). There were no significant diet order effects on energy intake, body weight, or body composition changes between UPF â MPF and MPF â UPF groups.CONCLUSIONS:
Diet order significantly affected energy intake, body weight, and body fat in a 4-wk crossover inpatient diet study varying in macronutrients, but not in a similarly structured study varying in ultraprocessed foods. This trial was registered at clinicaltrials.gov as NCT03407053 and NCT03878108.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Am J Clin Nutr
Año:
2024
Tipo del documento:
Article
País de afiliación:
Estados Unidos