Self-described evening chronotypes are more likely to consume meals later in the day that contain more sucrose and saturated fats compared with self-described morning chronotypes, putting them at greater risk for developing obesity, according to a Finnish study.
“Recent literature suggests that timing of energy intake may have major effects on metabolic health,” Mirkka Maukonen, of the National Institute for Health and Welfare in Helsinki, and colleagues wrote. “Animal trials as well as intervention and epidemiological studies on humans have shown that abnormal circadian timing of energy intake may lead to metabolic dysfunctions and weight gain. Whether chronotype affects timing of energy intake and its association with metabolic health is not well known.”
Maukonen and colleagues analyzed data from 1,854 adults participating in the 2007 FINRISK study, which assessed cardiovascular risk factors in a random sample of adults from Finland. Participants completed the Morningness-Eveningness Questionnaire (MEQ) and 48-hour dietary recalls to measure mean daily energy and macronutrient intake in the evening (8 p.m. to 2:59 a.m.) and morning (3 a.m. to 9:59 a.m.). The timing of energy and macronutrient intake also was stratified by weekdays and weekends. A shortened version of the MEQ was used to assess chronotype; score ranged from 6 (extreme eveningness) to 27 (extreme morningness).
Within the cohort, 49% were considered morning chronotypes; 39% intermediate; 12% were evening types; mean morningness–eveningness score was 17.9. There were no between-group differences for total daily energy intake (P = 1). However, evening chronotypes had a lower daily intake of protein vs. morning chronotypes (P = .017), and energy “intake peaks” were on average 1 hour later for evening types vs. morning types, the researchers noted.
In the morning, evening types had 350 kJ lower energy intake vs. morning types, corresponding to 4% less total energy intake in the morning (P < .001). Evening types also had a lower intake of all macronutrients vs. morning types (P < .01), except for sucrose intake, which was higher.
In the evening (after 8 p.m.), evening types had an average of 430 kJ higher energy intake vs. morning types, corresponding to a 6% higher energy intake (P < .001). Evening types also consumed 1.1% more energy units of sucrose, 5% more energy units of fat and 1.5% more energy units of saturated fatty acids (P < .05).
“Furthermore, evening types seemed to have more irregular meal times and twice as many eating occasions at the weekend than morning types,” the researchers wrote. “Thus, from these data for evening types as compared with morning types, a consumption pattern with more sucrose in the morning, and that with more sucrose and more fat in the evening emerged.”
The researchers noted that later energy intake among evening types may provide an explanation for their unhealthier dietary habits, adding that energy intake timing may have a substantial effect on metabolism independent of total energy intake and quality of diet.
“The postponed timing of energy and macronutrient intake of evening types with unfavorable dietary patterns may put them at higher risk [for] obesity and metabolic disturbances in the future,” the researchers wrote. “This hypothesis, however, requires longitudinal exploration in future studies.” – by Regina Schaffer
Disclosure: One researcher reports receiving personal fees from Dila, Finnair, Helen, Helsinki Fair, Heureka, Labquality, Lundbeck, MCD-Team, Mercuria Business College, MSD Finland, Servier Finland, Speakersforum Finland, Vaestoliitto Fertility Clinics, YTHS, and reports relationships with Duodecim Medical Publications, Oxford University Press and Terve Media.