Every November, most people quietly promise, “I’ll start after the holidays.” But the data tell a different story: the average adult gains a small but persistent amount of weight between mid-November and early January—and much of it sticks into spring and summer, contributing to year-over-year creep. In a prospective study published in the New England Journal of Medicine, average holiday gain was ~0.37 kg (about 0.8 lb), with heavier individuals gaining more—and failing to fully lose it later. That “small” gain, repeated annually, drives long-term weight increase. 

This isn’t just a U.S. effect. A cross-country analysis found body weight rose about 0.5% in the 10 days after Christmas versus before, reinforcing that holiday periods reliably nudge weight upward. More recent reviews confirm the pattern: holidays bring measurable upticks in weight across age groups. 

Why holidays drive gain (and why starting now helps)

1) Sleep debt → stronger hunger signals.

Even short-term sleep curtailment lowers leptin (satiety) and raises ghrelin (hunger), increasing appetite—exactly the combo many of us experience during late-night parties and travel. Prior lab studies show these hormonal shifts after just a night or two of short sleep. Protecting sleep now blunts that “always hungry” holiday feeling. 

2) Chronic stress → preference for hyper-palatable foods.

Acute stress can suppress appetite, but ongoing stress tends to push us toward energy-dense foods. Cortisol reactivity is also linked to greater intake of sweet/fatty foods and to central fat deposition—making “busy season” a perfect storm. Building stress-management routines before the peak can reduce the drive to graze. 

3) Small daily surpluses add up—and linger.

Physiology models show the body adapts slowly to shifts in intake; a modest daily calorie surplus produces gradual, long-lasting weight gain. In other words, it’s the pattern (a few hundred extra calories most days for several weeks), not a single feast. Starting a structure now (protein targets, fiber, movement) narrows that surplus window. 

4) Habits need lead time.

Behavioral data suggest habit automaticity typically takes weeks to months (median ~66 days). If you start in late November, you’re already building momentum while others are “waiting for Monday.” By January, your routine is practiced—not brand-new. 

The practical play: “Reset Before 2026”

• Anchor sleep (7–9 hours) and a consistent wake time to stabilize hunger hormones. 
• Front-load protein + fiber to reduce passive overeating when treats appear. (Supports satiety and lowers the size of any surplus.) 
• Schedule movement micro-wins (10–20 minute walks, brief lifts) to blunt stress and improve appetite regulation. 
• Use structured supports so you’re not relying on willpower during peak temptation.

How Health Collective fits in

• Supernova Experience: 4-week guided reset aligning nutrition, movement, and stress tools with women’s physiology so holiday weeks don’t become weight-gain months.
• Peptide Protocols (GHK-Cu, BPC-157, NAD+, GLOW): Target energy, recovery, skin/hair glow, and resilience—so your body feels better while you execute the plan. (Peptides complement—but don’t replace—habit scaffolding.)

Bottom line: The average holiday gain may look small on paper, but it’s sticky. Start now, and you convert the most tempting weeks of the year into your head start on 2026—lighter, stronger, and already in rhythm.