Early time-restricted eating improves markers of cardiometabolic health but has no impact on intestinal nutrient absorption in healthy adults

Early time-restricted eating (eTRE) improves aspects of cardiometabolic health. Although the circadian system appears to regulate nutrient absorption, little is known about the effects of eTRE on intestinal absorption. In this randomized crossover trial, 16 healthy adults follow a controlled, weight maintenance diet for 9 days, consuming all calories between 0800 and 1400 (eTRE schedule) or 0800 and 2000 (control schedule). We measure the energy content of the diet, stool, and urine with bomb calorimetry and calculate intestinal energy absorption. The eTRE schedule is more effective than the control eating schedule for improving markers of cardiometabolic health, including 24-h mean glucose concentrations and glycemic variability, assessed as the mean amplitude of glycemic excursions. However, eTRE has no effect on intestinal energy and macronutrient absorption, gastrointestinal transit time, colonic hydrogen gas production, or stool microbial composition, suggesting eTRE does not impact gastrointestinal function. This trial is registered (ClinicalTrials.gov: NCT04877262).

Amino Acid Intake and Conformance With the Dietary Reference Intakes in the United States: Analysis of the National Health and Nutrition Examination Survey, 2001-2018

BACKGROUND

The lack of complete amino acid composition data in food composition databases has made determining population-wide amino acid intake difficult.

OBJECTIVES

This cross-sectional study characterizes habitual intakes of each amino acid and adherence to dietary requirements for each essential amino acid (EAA) in the US population.

METHODS

Food and Nutrient Database for Dietary Studies ingredient codes with missing amino acid composition data were matched to similar ingredients with available data so that amino acid composition could be determined for 100% of foods reported in the dietary intake assessment component of NHANES. Amino acid intakes during NHANES 2001-2018 (n = 72,831; ≥2 y) were calculated as relative (mg·kg of ideal body weight^-1·d^-1) intakes. Data from NHANES 2011-2018 were used to determine the percentage of population consuming less than that recommended by the DRIs for each EAA by age, sex, and race/ethnicity.

RESULTS

Relative intakes of EAAs and NEAAs were greatest in those 2-3 y and lowest in older individuals (≥71 y or ≥80 y). In females aged 2-18 y, relative intakes of EAAs were lowest in non-Hispanic White (NHW; histidine, lysine, threonine, methionine, and cysteine) and non-Hispanic Black (NHB; valine, isoleucine, leucine, phenylalanine, tryptophan, and tyrosine) populations and highest in the Asian population. In females aged ≥19 y, relative intakes were lowest in NHW (lysine and methionine only) and NHB populations and highest in the Asian population. In males aged 2-18 y, relative intakes of EAAs were lowest in the NHB population and highest in the Asian population. In males ≥19 y, relative intakes were lowest in NHB and NHW (lysine only) populations and highest in the Hispanic population. Less than 1% of individuals aged ≥19 y did not meet the Estimated Average Requirements for each EAA.

CONCLUSIONS

EAA intakes in the US population exceed recommended minimum population requirements. Future studies can use the method described here to quantify amino acid intake and examine relationships with health and disease.