The question
Eating late has been linked to weight gain, but clock time can mislead. Two people can eat dinner at 8 pm while their body clocks sit hours apart. The study asked whether meal timing relative to each person's own body clock is linked to body fat.
How meal photos made it possible
To answer that, researchers needed exact meal times from everyday life, not from memory. For 7 consecutive days, participants used MealLogger to photograph every meal, snack and drink except water, with an object of known size in the frame for portion estimates. Each photo was time-stamped and reached study staff through the web straight away, so dietary staff could follow up within 24 hours if anything was unclear.
Logging held up: 93% of participants recorded meals on all 7 days and every participant logged at least 6 days.
What they found
Participants with higher body fat reached the midpoint of their daily calories 1.1 hours closer to melatonin onset, the start of the biological night, than lean participants.
“These results provide evidence that the consumption of food during the circadian evening and/or night, independent of more traditional risk factors such as amount or content of food intake and activity level, plays an important role in body composition.”
Reading the results carefully
This was a cross-sectional study of college-aged adults, so it shows an association, not cause and effect. The authors point to controlled trials as the next step. Their findings are one reason meal timing is worth tracking alongside what people eat.
Why it matters for Metabite
The study shows what a photo-based food journal can do in clinical research: high adherence in everyday life, a precise time on every meal, and a record that professionals can review and code. Every meal logged in Metabite today still carries its time, so care teams can see when people eat as well as what. The study was run by the hospital research team, using MealLogger as its meal-recording tool.
MORE RESEARCH The science behind the coaching: research by our team