- One of the most common reasons you're not losing weight is eating more than you think. In a small NEJM study of 10 adults with obesity, people underreported their food by 47% and overreported their exercise by 51% [1].
- Weight loss from dieting often stalls around 6 months [2]. A smaller body needs fewer calories, so the same diet creates a smaller calorie deficit.
- Water shifts and new muscle can hide fat loss on the scale, while short sleep and stress can slow it. In a trial of 80 adults, sleeping 1.2 hours more per night cut intake by 270 calories a day [3].
- Some medical conditions and medications make losing weight harder. A healthcare provider can check for causes like hypothyroidism.
You're eating better and moving more, but the scale won't budge. That's common, and most stalls have a clear cause.
Read on for 12 reasons you may not be losing weight, what the research says and what to try next.
12 reasons at a glance
Stalled weight loss has 12 common causes, each with a simple first step.
| Reason | A sign it might be you | First thing to try |
|---|---|---|
| 1. Eating more than you think | You estimate portions by eye | Weigh and log food for 1 week |
| 2. Calories in drinks | Juice, soda, alcohol or coffee drinks most days | Swap to water, tea or black coffee |
| 3. Plateau | Steady loss, then a stall | Recalculate your calorie needs |
| 4. Water or muscle changes | Clothes fit better, scale doesn't move | Track your waist and weekly average |
| 5. Eating back exercise calories | Hungrier on workout days | Don't add food for exercise |
| 6. Low protein and fiber | Hungry soon after meals | Add protein and vegetables to meals |
| 7. Short sleep | Under 7 hours most nights | Aim for 7 or more hours |
| 8. Chronic stress | Stress eating, poor sleep | Build in daily stress relief |
| 9. A medical condition | Fatigue, feeling cold, irregular periods | Ask your provider about blood tests |
| 10. A medication | Weight gain after starting a new drug | Ask your prescriber about alternatives |
| 11. Unrealistic pace | Expecting more than 2 pounds a week | Judge progress over months |
| 12. Age or menopause | Less strength, more fat around the middle | Add strength training |
12 reasons you're not losing weight
Weight loss usually stalls because something quietly shrinks your calorie deficit. Here's how each cause works and what helps.
1. You're eating more than you think
Eating more than you realize is one of the most common reasons weight loss stalls, because it cancels out your calorie deficit. In a 1992 NEJM study, 10 adults with obesity said they ate under 1,200 calories a day. They actually underreported their food by 47%, and their metabolism was normal [1]. What helps: weigh and log everything you eat for one week.
2. Drinks are adding hidden calories
Calories from drinks don't fill you up the way food does, so you don't eat less later to make up for them. In a crossover study of 15 adults, people ate less food during 4 weeks of daily jelly beans but not during 4 weeks of soda with the same calories. They gained weight only during the soda weeks [4]. What helps: switch to water, unsweetened tea or black coffee for most drinks.
3. You've hit a weight loss plateau
A weight loss plateau is a stall that happens as your body adjusts to a smaller size. In a review of 80 studies, results from diets and older weight-loss medications typically leveled off around 6 months [2]. Your body may also burn fewer calories than expected. Six years after a TV weight-loss competition, 14 contestants burned about 500 fewer calories a day at rest than predicted [5]. What helps: recalculate your calorie needs and add strength training. See how to break a weight loss plateau.
4. You're holding water or gaining muscle
The scale can hide fat loss because it weighs water and muscle too. Your body stores carbs as glycogen with 3 to 4 parts water, so a carb-heavy day can raise your weight overnight [6]. Strength training can add muscle while you lose fat, so you may lose inches but not weight. What helps: track your waist and weekly average weight, not single days.
5. You're eating back your exercise calories
Working out but not losing weight often happens because exercise burns fewer calories than people assume. A 2012 analysis of exercise trials found people lost less than predicted, mainly because workouts burned fewer calories than expectedand people ate more [7]. In a Stanford study of 60 adults, no wrist tracker estimated calories burned within 20% [8]. What helps: keep exercising, but don't eat extra to "earn back" workouts.
6. You're low on protein and fiber
Protein and fiber help you feel full, which makes a calorie deficit easier to keep. A 2015 review found higher-protein diets modestly improve fullness and help protect lean mass during weight loss [9]. In the POUNDS Lost study of 345 adults on calorie-reduced diets, fiber intake was the strongest predictor of weight lost over 6 months [10]. What helps: build each meal around protein plus vegetables, fruit or whole grains.
[Related reading box: How much protein do you need to lose weight? (/learn/protein-for-weight-loss/) · What causes a weight loss plateau? (/learn/weight-loss-plateau/) · Wegovy®: how it works (/medications/wegovy/) · Weight loss: causes and treatment (/conditions/weight-loss/). Editor to confirm live URLs.]
7. You're not getting enough sleep
Short sleep can slow fat loss even when you stick to your diet. In a 14-day trial of 10 adults on the same diet, sleeping 5.5 instead of 8.5 hours cut the share of weight lost as fat by 55% [11]. Short sleep also raises the hunger hormone ghrelin and lowers leptin, a fullness hormone [12].
In a trial of 80 overweight adults, sleeping about 1.2 hours more per night cut intake by about 270 calories a day [3]. What helps: aim for at least 7 hours a night, with a regular bedtime.
8. You're under chronic stress
Research suggests long-term stress can make weight loss harder. Chronic stress raises cortisol (the main stress hormone), which is linked to more appetite, cravings and belly fat, though people react differently [13]. What helps: build in daily stress relief, such as a walk, breathing exercises or time with people you trust.
9. A medical condition is slowing you down
Some health conditions change your metabolism or appetite and make losing weight harder. Ask your provider about:
- Hypothyroidism: An underactive thyroid slows metabolism. Nearly 5 in 100 Americans 12 and older have it [14].
- PMOS (formerly PCOS): Polyendocrine metabolic ovarian syndrome is a hormone condition often linked to insulin resistance and weight gain [15, 16].
- Insulin resistance: Excess weight and a large waist raise your risk. Losing 5% to 7% of body weight lowered the chance of type 2 diabetes in the Diabetes Prevention Program [17].
- Cushing's syndrome: Too much cortisol causes weight gain in the face, around the neck, the midsection and upper back. It's rare, affecting about 40 to 70 people per million [18].
Good to know
PCOS was renamed PMOS in May 2026 by a global expert consensus. Both names are in use during the transition [16].
What helps: ask about blood tests, such as a thyroid test and an A1C test for blood sugar.
10. A medication is working against you
Some prescription drugs can cause weight gain or make losing weight harder. A 2018 review linked weight gain to certain antidepressants (amitriptyline, mirtazapine, paroxetine), antipsychotics (olanzapine, clozapine), diabetes medicines (insulin, sulfonylureas) and beta-blockers (atenolol, metoprolol) [19]. Long-term prednisone use was linked to gains of about 4 to 13 pounds [19]. What helps: don't stop medication on your own. Ask your prescriber about weight-neutral options.
11. Your expectations don't match a healthy pace
Healthy weight loss is slower than most people expect. The CDC says people who lose about 1 to 2 pounds a week are more likely to keep it off [20]. Losing 5% of your body weight can lower your risk of heart disease and type 2 diabetes [20]. What helps: judge your progress over months, not days.
12. Your body is changing with age and menopause
Muscle mass and strength tends to decline with age, a process called sarcopenia [22].
Menopause changes body composition, which can slow your progress. In the SWAN study of midlife women, the rate of fat gain doubled at the start of the menopause transition, while lean mass began to decline [21]. What helps: add strength training at least 2 days a week and keep your protein intake steady.
Do supplements or products help you lose weight?
No, there's little scientific evidence that weight-loss supplements work, according to the NIH Office of Dietary Supplements [22]. The FDA doesn't review supplements before they're sold, and some can interact with medications [22].
How do you know if you're still making progress?
Track more than one measure, because the scale alone can hide real progress. Use a weekly average weight, measure your waist every 2 weeks, and notice how your clothes fit. As a rule of thumb, if none of these improve after about 3 months of steady effort, talk with a healthcare provider.
Not losing weight on Wegovy®, Zepbound®, Ozempic® or Mounjaro®?
Slow weight loss in the first months on a GLP-1 medication is common, partly because the dose starts low. Wegovy® (semaglutide) injection starts at 0.25 mg a week and increases every 4 weeks, reaching the usual 2.4 mg maintenance dose after 16 weeks. Wegovy® tablets start at 1.5 mg a day and step up every 30 days [23]. Zepbound® (tirzepatide) starts at 2.5 mg a week, with increases at least 4 weeks apart [24].
Results build over a year or more. In the STEP 1 trial of 1,961 adults, people taking Wegovy® plus lifestyle changes lost 14.9% of their weight on average over 68 weeks [25]. In the SURMOUNT-1 trial of 2,539 adults, people on the highest Zepbound® dose lost 20.9% on average over 72 weeks [26].
Ozempic® (semaglutide) and Mounjaro® (tirzepatide) are FDA-approved for type 2 diabetes, not weight loss [27, 28]. If a steady dose hasn't helped after a few months, ask your prescriber about your dose and the other reasons on this list. Read more about Wegovy® and Zepbound®.
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When to see a healthcare provider
See a healthcare provider if steady changes haven't moved your weight or waist after a few months. Also make an appointment if you have:
- Weight gain you can't explain
- Tiredness or feeling cold (possible thyroid signs)
- Irregular periods or extra facial hair
- Weight gain that started after a new medication
- Binge eating that feels out of your control
Call 911 or go to the nearest ER if you have chest pain, sudden severe shortness of breath, or sudden leg swelling with trouble breathing.
Bottom line
- Stalled weight loss often comes down to eating more than you realize, drink calories or a normal plateau. Water and new muscle can hide fat loss, while short sleep and stress can slow it.
- If steady changes haven't helped after a few months, see a healthcare provider. A medical condition or medication may be involved, and treatments can help.
How we source this
Our editorial team relies on primary sources, including peer-reviewed studies, FDA labels and government health agencies. Read our editorial policy.
Frequently asked questions
How long does a weight loss plateau last?
A weight loss plateau usually lasts until something changes, such as your calorie intake or activity. Plateaus are common around 6 months into a diet [2]. Recalculating your calorie needs at your new weight, adding strength training and sleeping at least 7 hours can help restart progress.
Why am I gaining weight in a calorie deficit?
Short-term weight gain in a calorie deficit is usually water, not fat. Your body stores carbohydrates as glycogen with 3 to 4 parts water, so a carb-heavy day can raise the scale overnight [6]. If the gain lasts several weeks, check how accurately you're tracking food.
Does muscle weigh more than fat?
A pound of muscle weighs the same as a pound of fat, but muscle takes up less space. That's why strength training can shrink your waist while the scale barely moves. Measuring your waist every 2 weeks shows this change better than weight alone.
Can hypothyroidism stop you from losing weight?
Hypothyroidism can slow your metabolism and cause weight gain, which makes losing weight harder. It affects nearly 5 in 100 Americans ages 12 and older [14]. A blood test can check your thyroid, and thyroid hormone medicine treats it.
How long does it take to lose weight on Wegovy® or Zepbound®?
Weight loss on Wegovy® or Zepbound® builds gradually, with the biggest results after a year or more. Both start at a low dose that rises over several months [23, 24]. In trials, average weight loss was 14.9% at 68 weeks on Wegovy® and up to 20.9% at 72 weeks on Zepbound® [25, 26].
Sources
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- Shcherbina, A., Mattsson, C. M., Waggott, D., et al. (2017). Accuracy in wrist-worn, sensor-based measurements of heart rate and energy expenditure in a diverse cohort. Journal of Personalized Medicine, 7(2), 3. https://doi.org/10.3390/jpm7020003
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- Miketinas, D. C., Bray, G. A., Beyl, R. A., Ryan, D. H., Sacks, F. M., & Champagne, C. M. (2019). Fiber intake predicts weight loss and dietary adherence in adults consuming calorie-restricted diets: The POUNDS Lost study. Journal of Nutrition, 149(10), 1742-1748. https://doi.org/10.1093/jn/nxz117
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