Holiday weight gain: what the research actually measured

Holiday weight gain is real, but it is usually small. When researchers actually weighed people before and after the holidays, the average gain was roughly 1 to 2 lb (0.4 to 0.9 kg) in most studies of adults. That’s not the 5 lb that gets repeated every December. The catch is that the gain often stays, and a few simple habits, mostly keeping an eye on things, seem to help.

This page walks through what those studies measured, who was in them, and what that means for your own season. It is not a reason to skip the party.

Key takeaways

• A 2000 NIH study of 195 adults found an average holiday weight gain of about 0.8 lb (0.37 kg), far below the 5 lb people often claim.
• A 2017 review found adults gained about 1 to 2 lb (0.4 to 0.9 kg) over the holidays across studies. Averages hide a wide spread: some people gain more, some lose.
• The gain tends to stick. In the NIH study it was not reversed by the following fall.
• The habit the holiday trials tested most is self-monitoring: in two trials, people who weighed themselves regularly over the holidays did not gain on average, while comparison groups did.
• A rough log you keep beats a perfect one you drop. One message per meal is enough.

How much weight do people gain over the holidays?

On average, about a pound. That is the honest answer from the studies that put people on a scale instead of asking them to remember.

The best-known one is a prospective study in the New England Journal of Medicine (Yanovski et al., 2000, PMID 10727591). Researchers at the National Institutes of Health weighed a convenience sample of 195 adults four times, six to eight weeks apart. To hide the main outcome, they also recorded other vital signs and health questions.

Mean weight rose about 0.8 lb (0.37 kg) between mid-November and early or mid-January. It did not change significantly before the holidays or after them. The authors put it plainly: the average holiday weight gain is “less than commonly asserted.”

A 2017 narrative review of the research (Díaz-Zavala et al., Journal of Obesity, PMID 28744374) found the same pattern. In studies of adults, a significant gain of 0.4 to 0.9 kg was consistently seen over the holiday season. It defines the season as the last week of November to the first or second week of January.

What the studies found, side by side

Different studies measured different people over different windows, so the numbers below are not a ranking. They show how much the answer depends on who was weighed.

Three things stand out.

• Most averages land near a pound. Four of the five groups gained between 0.37 and 0.74 kg.
• One group did gain more than 5 lb. In the 2019 University of Georgia trial, the control group gained 2.65 kg on average. So the folklore number is not impossible. It just isn’t typical across studies.
• The college students mostly gained lean mass. In the 2025 Texas study, body fat percentage did not change, and lean mass went up. The authors read it as a healthy change, not a worrying one.

The short version: expect the season to move the scale a little, and expect your number to differ from anyone else’s.

Why a small gain still matters

The size is small. The problem is that it doesn’t always go away.

In the NIH study, people were weighed again in late February or March, and then in the following September or October. Compared with the start, they were 0.48 kg heavier in late winter, and they had not lost it by the next fall. The authors suggested that this yearly gain likely adds to the slow weight gain many adults see over the years.

The Georgia trial found something similar over a shorter span. The control group lost some weight in the 14 weeks after the holidays but kept 57 percent of what it had gained, according to the study’s abstract.

The 2023 Australian study adds a useful detail. With 368 adults weighing themselves at home (361 had data for the Christmas comparison), it found weight also rises a little every weekend and dips during the week. The Christmas and New Year spike sat on top of that weekly rhythm. In other words, holidays are a bigger, longer version of a pattern most people already live with.

None of this makes the holidays a problem to solve. It makes them a few weeks worth noticing.

What helped people not gain?

Self-monitoring. It is the habit the holiday trials tested most, and it is simple.

• Regular weighing, UK. In a randomized trial of 272 adults in Birmingham, one group was asked to weigh themselves at least twice a week (ideally daily), record it, and reflect on the trend. They also got 10 tips and a sheet showing festive foods as minutes of walking or running. The comparison group got a healthy living leaflet.

  The weighing group’s average change was -0.13 kg, essentially no change, while the leaflet group gained 0.37 kg (Mason et al., BMJ, 2018). The adjusted difference was 0.49 kg.

• Daily weighing with a graph, US. In the Georgia trial, the group that weighed in daily on Wi-Fi scales and saw a graph of their trend had no change in weight over the holidays. The control group gained 2.65 kg (Kaviani et al., Obesity, 2019).

• Consistent self-monitoring, US. An older trial of 57 people in a weight-control program added phone calls and daily mailings focused on self-monitoring during the two weeks from Christmas to New Year. That group self-monitored more consistently and managed their weight better than the comparison group, though both groups found the holidays hard (Boutelle et al., Health Psychology, 1999, PMID 10431937).

A word of caution. A 2025 systematic review pooled five adult studies of holiday interventions and found a mean difference of 0.99 kg in favor of the intervention groups. But the result was not statistically significant, and the evidence was rated very low certainty (Guerrero-Magaña et al., Obesity Reviews, PMID 39275907). Ten of its 12 included studies were from the United States. Self-monitoring looks promising. It isn’t proven to work for everyone.

We read the research this way. The trials that worked didn’t ask people to skip the party. They asked people to keep looking. That is the same idea behind keeping a food diary: noticing is most of the work.

How to get through the season without the stress

Here is what we would do, based on that research. None of it is a diet.

1. Keep logging, just more loosely. One message for the whole plate is enough. A rough log you keep through December beats a detailed one you drop on December 20.
2. Log the big days in a sentence. “Holiday buffet, two plates, one slice of pie” is a useful entry. For the arithmetic of a typical plate, see Thanksgiving dinner calories.
3. Name the hidden fat. Butter, oil and cream add a lot of energy to holiday food, and they’re the part a photo can’t see. It is the usual blind spot of AI calorie counters, so say it out loud.
4. Keep the rest of the week normal. The Australian data shows weekends already nudge the scale. In our view, a normal Tuesday after a big Saturday does more than any rule.
5. Expect a little noise. One heavier morning after a big dinner doesn’t tell you much on its own. Look at the trend over weeks, not one reading.
6. Let a missed day go. Missing a day breaks nothing. Log the next meal and keep going.

If you want to stop logging entirely for a few days, that is a fair choice too. Pick up again when the routine comes back.

Where Getfiit fits

Getfiit is an AI nutrition and fitness coach that lives in WhatsApp. You send a photo, a voice note or a sentence about a meal, and it sends back calories and macros. You can log a weigh-in in the same chat, and it checks in with you once a day at a time you pick. There’s no new app to install.

Here is an illustration of what a holiday log can look like. It is an example of the kind of exchange, not a measured result:

9:41

Getfiit

online

Today

0:08

office holiday party, two plates from the buffet, mostly turkey sliders and cheese, plus a glass of wine

12:38

Sounds like a good party. Roughly how many sliders, and was the wine a regular glass?12:39

three sliders, regular glass12:40

Got it, logged as one entry for the evening. Want me to check in tomorrow at the usual time?12:41

weighed in at 174 lb this morning12:42

Logged. One morning's number moves around, so the trend over a few weeks says more than today's reading.12:43

As of November 3, 2026, Getfiit costs $19.99 a month after a 3-day free trial, and you can cancel anytime. The how it works section on the home page shows the rest.

A note on tracking during the holidays

Tracking is not for everyone, and the holidays can make it harder. If counting food or weighing yourself brings on stress, restriction or guilt, or you have a history of disordered eating, it may do more harm than good. The National Institute of Mental Health has information on eating disorders. Talk with a doctor or a registered dietitian about what is right for you.

Frequently asked questions

What is the average holiday weight gain?

In most studies of adults, roughly 1 to 2 lb (0.4 to 0.9 kg) between late November and early January, per a 2017 review. The NIH’s 2000 study found about 0.8 lb (0.37 kg).

Do people really gain 5 pounds over the holidays?

Not on average. The 5 lb figure is the one the NIH researchers set out to test, and their sample gained less than a pound. One 2019 control group did gain about 5.8 lb, which shows how much samples vary.

Does holiday weight go away on its own?

Not always. In the NIH study, the holiday gain had not reversed by the following fall. In the 2019 Georgia trial, the control group kept 57 percent of its gain 14 weeks later.

How can I avoid holiday weight gain?

The habit the holiday trials tested most is self-monitoring. In two trials, people who weighed themselves regularly did not gain on average. In a third, people who self-monitored more consistently managed their weight better, though both groups found the season hard. The evidence is still limited, so treat it as a helpful habit, not a guarantee.

Do college students gain weight over the holidays?

In one 2025 study of 47 Texas undergraduates, yes, a little: about 1.6 lb (0.74 kg) on average from before Thanksgiving break to January. Body fat percentage did not change, and lean mass went up. More answers like this are in the FAQ on the home page.

Your next step

Pick one habit for the season: a regular weigh-in (the UK trial asked for at least twice a week), or one message per meal. Keep it going through New Year’s Day, loosely, and see what your own numbers say.