in autumn people eat more and move less. In the study by Ma and colleagues (European Journal of Clinical Nutrition, 2006; 593 adults tracked from 1994 to 1998), calorie intake in autumn ran 86 kcal a day above spring, peaking in early November, while physical activity dropped to its yearly low in winter. Across the whole year body weight swung by only about 0.5 kg.The sleepiness is about light: a short day shifts melatonin production. Three levers work — daylight in the first hour after waking, a protein breakfast, and movement you refuse to cancel.
Every September the same story repeats itself: the summer routine falls apart inside two weeks, workouts slide to "next month," and the evening ends with biscuits you never planned to eat. The convenient explanation is that you went soft after the holidays. The data says something else — the season really does shift both appetite and sleep, just not by as much as everyone assumes.
Do People Really Eat More in the Fall?
Yes, and it has been measured. Researchers followed 593 people aged 20 to 70 for four years, from 1994 to 1998, recording food, activity and body weight season by season.
What came out:
- calorie intake in autumn was higher than in spring by an average of 86 kcal a day;
- the peak lands in early November, the low point in early May;
- physical activity is highest in spring and lowest in winter;
- body weight swings across the year by roughly 0.5 kg, peaking in winter.
Look hard at that last number. The seasonal shift is real, but modest. Autumn does not add five kilos by itself — 86 kcal a day is about half a banana. The problem is what it coincides with: a fall in activity and a routine quietly coming apart. Together they turn "half a banana" into a real gain.
Why the Craving Is Specifically for Sugar and Bread
The craving has a biochemical plot, and it is a logical one.
The shorter the day, the lower serotonin activity — the messenger behind calm and steady mood. The body looks for a fast way to lift it and finds carbohydrates: they trigger an insulin release, and insulin helps tryptophan, serotonin's precursor, get into the brain. Twenty minutes after the pastry you feel a little calmer, and the brain files that away.
Hence the practical conclusion: an autumn craving is not about hunger, it is about mood. That is exactly why willpower doesn't close it and sleep, light and protein do.
The second layer is circannual (yearly) rhythms in the appetite hormones: reviews of seasonal metabolic changes describe leptin, the fullness signal, falling towards autumn while ghrelin, the hunger signal, rises. In animals this mechanism builds a winter reserve. In humans it survives in a weakened form — a background hum, not a verdict.
Where the Sleepiness Comes From
One number decides everything here: how much light reaches your eyes.
Melatonin, the sleep hormone, is produced in darkness and suppressed by bright light. In July you wake in a lit room and melatonin production stops on its own. By late October the alarm goes off in the dark: melatonin is still being produced, the brain concludes the night isn't over, and that is the feeling of being pulled out of the middle of a sleep. Once the clocks go back at the end of October, the morning gets a brief reprieve and the evening goes dark before you leave work — at northern latitudes the total daylight keeps shrinking either way.
The scale of the difference is routinely underestimated. Illuminance is measured in lux:
- an overcast autumn day outdoors — roughly 1,000–10,000 lux;
- a well-lit office or living room — around 300–500 lux.
So even a grey sky is tens of times brighter than a room with every lamp on. Your body separates "day" from "night" by exactly this number, and as far as the retina is concerned, a working day spent indoors is a long dusk.
When It Is No Longer Just the Seasonal Slump
Seasonal sluggishness is normal. But it has a clinical relative — seasonal affective disorder (SAD), described as a distinct condition back in the 1980s. It is recognised not by mood in general but by a stable set of signs that appear in autumn and lift in spring:
- low mood most of the day, nearly every day, for longer than two weeks;
- sleeping longer than usual but never waking up rested;
- pronounced carbohydrate cravings and weight gain;
- loss of interest in things that used to be enjoyable;
- a drop in energy that gets in the way of work and other people.
If that is you, it isn't a discipline problem, it is a reason to see a doctor. SAD is treatable, light therapy among the recognised methods, and there is no sense in waiting for spring.
A separate topic is vitamin D: from autumn the sun at northern latitudes no longer delivers the radiation you need, and levels fall in most people. It isn't the cause of your sleepiness on its own, but it is part of general well-being — how to handle the dosing is in the vitamin D guide.
What Actually Helps
The levers, ordered by how much they move.
| Lever | What it does | How to apply it |
|---|---|---|
| Daylight in the first hour after waking | cuts off melatonin production, sets the rhythm of the day | 15–30 minutes outdoors or by a window, no sunglasses |
| A protein breakfast | holds fullness until lunch, blunts the pull towards fast carbs | 25–30 g of protein: eggs, cottage cheese, Greek yoghurt, fish |
| Movement you keep | offsets the seasonal drop in activity | not "gym or nothing" but 20–40 minutes of walking daily |
| A fixed wake-up time | stabilises the circadian rhythm | the same time ± 30 minutes, weekends included |
| Dimmer light in the evening | stops you blocking melatonin at night | warm light and fewer screens for the hour before bed |
| Carbs shifted, not removed | closes the craving without a blow-out | complex carbs towards dinner instead of a total ban |
| Coffee before 2 p.m. | keeps caffeine from stealing deep sleep | late coffee makes the next morning heavier |
Notice what is missing: not a single supplement. Autumn sleepiness is a problem of light and scheduling, and it is solved by the same two things. How much protein your own breakfast needs is in how much protein per day.
Why Autumn Weight Gain Isn't Really About Autumn
The data showed an annual weight range of about half a kilo — and people put on far more than that over the cold season. The gap isn't created by biology, it is created around it:
- the steps go first. Summer walks, cycling and time outdoors disappear all at once, and that is tens of thousands of steps a month. What it means for energy expenditure is unpacked in what NEAT is;
- training becomes weather-dependent. One session skipped because of rain quickly turns into the rule;
- food changes its job. In autumn it more often becomes a way to warm up and calm down rather than to end hunger;
- the sleep schedule drifts. Short sleep raises hunger by itself — the mechanism is in the sleep hygiene guide.
And if the scale has been stuck since September while "nothing changed in the diet," the audit list is the same one used for any weight-loss plateau: activity first, portions second.
The good news sits inside the bad news: if the gain is made by behaviour around the season rather than by the season, the levers stay in your hands.
the cheapest intervention autumn offers is getting outside in the first 30–60 minutes after waking, even for a quarter of an hour, even under a grey sky. It is light for the circadian rhythm, steps to replace the lost summer ones, and a start to the day that isn't the snooze button — all at once. Of everything on the list, it is the only item that costs nothing and fits into a walk you were taking anyway.
FAQ
Does the body really store fat for the winter?
Partly: seasonal shifts in leptin and ghrelin do exist. But the scale is modest — the measured difference is around 86 kcal a day, and body weight varies across the year by roughly 0.5 kg. Anything beyond that comes from lower activity, not from a metabolic "winter mode."
Why is waking up harder in autumn even when I sleep eight hours?
Because you wake in the dark and melatonin is still being produced. What helps is not sleeping longer but light straight after waking and a fixed wake-up time.
I'm hungry all the time in autumn — is that a vitamin deficiency?
Usually not. Check three things first: sleep, protein at breakfast, and how much daylight you get. If the complaints hold, blood tests make sense (ferritin and vitamin D first) — but starting with supplements "just in case" is the wrong end.
Do light boxes work?
For seasonal affective disorder, light therapy is a recognised method. For ordinary autumn sluggishness, try the free version first: real daylight in the morning is brighter than any lamp at home.
Should I cut calories in autumn so I don't gain?
It makes more sense to rebuild movement than to cut the plate: the seasonal drop in activity hits energy out harder than the seasonal appetite hits energy in.
The bottom line
Autumn sleepiness and food cravings are not weakness of character, they are a response to a shorter day: melatonin switches off later, serotonin activity drops, and the body asks for fast carbohydrates. But the scale of the seasonal effect is modest — 86 kcal a day more than in spring, and about 0.5 kg of weight range across the year. The real gain is made by what happens alongside it: the steps that vanished, workouts that became weather-dependent, and a sleep schedule that slid. Which is why the levers are simple: light in the morning, protein at breakfast, movement you keep, and the same wake-up time every day.
This article is for informational purposes and doesn't replace medical advice. If low mood, sleepiness and low energy last longer than two weeks and get in the way of ordinary life, that is a reason to see a specialist: seasonal affective disorder is treatable, and there is no need to wait for spring.
