Skip to content

25 Sneaky Reasons You're Gaining Weight When You're Doing Everything Right

Find out which common habits may be to blame for your weight gain and what you can do about it.
FACT CHECKED BY Alexa Mellardo

If the number on the scale keeps going up despite your best efforts, you're not alone. We spoke with the experts who share with us 25 super sneaky reasons you're gaining weight when you're doing everything right.

A recent survey conducted by OnePoll found that a staggering 95% of Americans have tried to shed excess weight in the past five years. Additionally, nearly half of the respondents said they've struggled with achieving their weight loss goals (and have actually gained weight). According to the poll, people's most significant roadblocks surrounding weight loss include maintaining willpower, lacking motivation, sticking to a healthy diet, and battling hunger.

So why is it so dang hard to lose weight and keep it off? To help solve this dilemma, we asked nutrition and weight loss professionals to weigh in (pun intended) on the most common reasons you're gaining weight when you're seemingly doing all the right things. Read on to discover what they are so you can conquer your weight loss woes. And if you're looking for further weight loss tips, check out 8 Little Things You Can Do Every Night To Lose More Weight.

You're only prioritizing workouts, not other activities.

fit senior woman at home demonstrates body parts to exercise after 60 with dumbbells

While exercise is an invaluable tool for losing weight, you can't expect to reach your weight loss goals if you work out for 30 to 60 minutes but are sedentary for the remainder of the day.

"Getting enough exercise is vital for overall health, but that means being active outside of workouts," Kate Meier, CPT, a certified personal trainer with Gym Garage Reviews, tells us. "Small actions like taking the stairs at work, walking the dog, or playing with your kids can significantly impact your metabolism and help you lose weight, but they're often overlooked."

You're underestimating portion sizes.

portioned plate with fish, grains, veggies, fruit, and a water glass

According to a study by Cornell University, people of average weight underestimate the number of calories they consume by nearly 20%, while overweight people underestimate it by nearly 40%. So at the end of the day, calories are still calories, regardless of whether you're eating healthy food. That's why paying close attention to portion sizes is essential when your health goal is weight management.

"Even if you're eating healthy foods, overeating may mean you're consuming too many calories," says Trista Best, RD, a registered dietitian with Balance One Supplements.

You're not adjusting your nutrition as you progress.

meal plan

A lesser-known fact about weight loss is that your body's needs and metabolism change after losing weight, according to research. To put it into context, a 110-pound person requires much fewer calories than a 220-pound person. That's because the smaller your body, the less energy it requires.

"As you lose weight, your body's caloric needs will change. So if you've noticed a lack of progress or weight gain after consistent weight loss, not readjusting your nutrition may be the culprit," explains Meier.

You're consuming too many calories through beverages.

latte with bread

Another one of the top reasons you're gaining weight is you're unknowingly consuming too many calories through beverages. Soda, juice, wine, beer, lattes. These beloved beverages, though enjoyable, are loaded with empty calories that provide very little nutritional value. If you're eating in a calorie deficit or to maintain weight but regularly consume these high-calorie beverages, you could be counteracting your weight loss efforts.

"Liquid calories from sodas, juices, and alcohol can add up quickly and contribute to weight gain. Stick with water or low to zero-calorie beverages and save your calories for nutrient-dense foods instead," says Best.

You're not sleeping enough.

older man with insomnia wakes up at night

Getting enough quality sleep is a critical aspect of any healthy weight loss plan, says the Sleep Foundation. In addition, research has shown that lack of sleep while dieting can negatively affect weight loss and lead to overeating by increasing the production of ghrelin (the hunger hormone).

"Sleep is essential for losing weight for various reasons, but it's easy to fall off track with this aspect of your fitness routine. Adults should aim to get about seven or more hours of sleep per night, and that sleep would ideally be uninterrupted," says Meier.

You're not getting enough protein.

casein protein shake with powder next to it

Among the three macronutrients—carbohydrates, protein, and fats—protein is the most satiating, meaning it makes you feel full faster and longer. Research shows that high-protein diets can reduce body weight and help prevent overeating.

"Whether it's from plant or animal sources, try to have a serving of protein at each meal or as a snack to increase satiety and prevent overeating," says Best.

The Best High-Protein Foods To Eat Every Day To Lose Your Gut

You're gaining muscle.

fit man demonstrating how to build muscle at gym machine

Did you know that gaining muscle could be a major reason you're gaining weight? Muscle is denser than fat, according to research. So if you've been hitting the weights and doing regular resistance training, odds are, you're not losing weight due to muscle gains.

"If you've truly been dedicated to a fitness plan and find that you're starting to gain weight, there's a chance you're actually gaining muscle," says Meier. "If you look like you're still getting fitter and notice slight differences, like your clothes fitting differently, but the scale shows a higher number, this is likely the case."

You're stressed out.

man stressed working on laptop

Learning to chill out can actually aid in weight loss, says one study.

"High stress levels can trigger the release of cortisol (the stress hormone), which can increase appetite and lead to overeating," Best explains. "Find a stress reduction method that works for you, or evaluate areas of stress that can be removed or reduced."

You're on medication that causes weight gain.

woman looking at medicine bottle

Many popular medications may have side effects such as weight gain. "However, this doesn't mean you should stop your medications, especially these types, but speak to your prescribing healthcare provider for ways to counteract this side effect," Best notes.

Your hormones are out of balance.

the word hormones on wooden cubes

Hormonal imbalances may be the culprit behind your weight loss woes. According to the Mayo Clinic, several hormones can affect how your body indicates that it requires food and uses energy. Too much cortisol and a low amount of thyroid hormones, for instance, can result in unintentional weight gain.

"Conditions such as polycystic ovary syndrome (PCOS) and thyroid disorders can cause weight gain," says Best. "Have thorough blood tests done annually or bi-annually to evaluate your hormone status and areas that could use improvement or balance."

You'll Never Lose Weight if You Still Do These 5 Things, Expert Says

Your muscles are inflamed.

inflamed muscles after workout concept

Inflammation is the root cause of many common diseases, research shows. Additionally, inflammation can make it more challenging to lose weight and easier to pack on extra pounds by heightening your risk of type 2 diabetes.

"When a particularly intense or new type of workout taxes your muscles, this can cause inflammation in tandem with delayed-onset muscle soreness, which can lead to some water weight gain as you recover," states Meier.

You're not getting enough physical activity.

woman on couch sedentary lifestyle concept

It should go without saying, but you're unlikely to shed pounds if you're not moving your body enough and expending energy.

"Even if you're eating well, if you're not moving your body enough, you may still gain weight," says Best. "Physical activity can also greatly reduce stress and provide you with feel-good hormones."

Drop 10 Pounds Fast With This 10-Minute Daily Workout

You're weighing yourself at a bad time.

woman stepping on scale

Typically, your weight is at its lowest point in the morning after you get out of bed and go to the bathroom, according to Healthline. It gradually rises throughout the rest of the day as you eat and drink. That's why it's critical to step on the scale at the same time daily.

"It's normal for weight to fluctuate, and a typical adult's weight can fluctuate by about five pounds in a single day," says Meier. "If you see the number on the scale going down for the most part, outlier weights may be chalked up to daily fluctuation. To better grasp your weight fluctuation, weigh yourself around the same time each day."

Your workouts have become stale.

woman doing dumbbell squats at home

You know it's time to switch up workouts when you've become bored and no longer feel tired afterward.

"If you do the same exercises repeatedly without any changes, your body adapts to them and they may not be as effective. Instead, try switching up your workouts or routine every few weeks to stimulate your muscles differently," advises Meier.

You're skipping meals.

skipping meal concept

You may think you're doing yourself a favor by skipping breakfast, lunch, or dinner, but delaying your hunger can cause overeating and weight gain. For example, a 2021 study published in Nutrients found that not eating dinner was linked to obesity and being overweight.

"Skipping meals can lead to overeating later on and can also slow your metabolism," explains Best. "You're also more likely to overeat at the following meal due to the excessive hunger you're likely experiencing."

5 Foods Everyone in Their 40s Should Eat for Faster Weight Loss

You have a medical condition you're unaware of.

seasonal depression

If you have an underlying health condition you don't know about, you may have more difficulty keeping weight off. Conditions such as sleep apnea, hypothyroidism, and depression can hinder weight loss and cause weight gain, according to WebMD.

"Many medical conditions are associated with weight gain, so it's important to visit your doctor if your weight changes significantly without any lifestyle changes," recommends Meier.

You're eating too quickly.

woman bloated from eating too fast, reasons you're gaining weight concept

In our lightning-paced world, it's easy to fall into the trap of checking items off our to-do lists without paying attention to what we're actually doing. So instead of scarfing down your next meal, practice mindful eating by eating slowly while paying close attention to your body's hunger signals, suggests Harvard Health Publishing.

"Eating too quickly can lead to overeating because your brain doesn't have enough time to register that you're full," says Best.

Your diet is too restrictive.

woman cutting and eating chicken with vegetables

Multiple studies have found that restrictive diets ultimately hinder weight loss and instead contribute to weight gain.

"When you go on highly restrictive diets, your body may be unable to handle coming off the diet. For example, individuals who go from a super low-carb diet to a regular balanced diet may gain a substantial amount of weight right out of the gate," says Meier. "Slow, steady, and balanced diets are the better route for sustainable weight loss."

You're eating too many processed foods.

bag of cookies

Another one of the sneaky reasons you're gaining weight? Indulging in processed foods! In general, processed foods come with a high calorie count, sugar, sodium, preservatives, unhealthy fats, and no nutrients, according to Down to Earth. This makes processed foods easy to overconsume and could be a reason why you're packing on extra weight.

"Processed foods often contain added sugars, fats, and salt, which can contribute to weight gain," says Best.

The 5 Worst 'Empty-Calorie' Foods Making You Gain Weight Faster

You're retaining water.

fitness woman drinking water on a run, concept of everyday habits for a flatter stomach that are easy

"Water weight is one of the factors that go into daily weight fluctuation, and being hydrated or dehydrated can lead to substantial losses or gains in a day," explains Meier. "Even when you lose weight quickly in a few days, much of it is often water. Dehydration can lead to short-term water retention, but long-term water retention can be associated with health issues and warrants a doctor's visit."

You're getting older.

woman weight gain concept from leading sedentary lifestyle

"As you age, your metabolism slows down, making it easier to gain weight. Speak to your healthcare provider or registered dietitian for tips on counteracting this side effect," Best advises.

A primary reason why weight loss is more challenging as you get older is that you naturally lose lean muscle. Muscle torches more calories when compared to fat. Therefore, a decline in muscle correlates to it being a greater challenge to utilize the calories you're consuming, Sanitarium explains.

Your genetics make it harder to lose weight.


Your genetics can impact your weight in several ways, says Harvard Health Publishing. For example, genes can impact metabolism, satiety, appetite, cravings, body-fat distribution, and the habit to eat as a stress-coping mechanism.

"Your genes can play a role in your body shape and how easily you gain weight. While you can't change your genetics, understanding the cause can help reduce frustration," says Best.

You're not eating enough fiber.

fiber foods concept

Fiber is an essential nutrient for healthy weight loss. For example, one study found that dietary fiber intake can promote weight loss and diet adherence in overweight and obese adults.

In addition to helping you feel full, fiber slows down the digestion process and helps prevent blood sugar spiking. This allows you to better manage your insulin and blood sugar response to food.

Eat These High-Fiber Snacks Every Day for Weight Loss, Dietitian Says

You don't get dressings or sauces on the side.

man pouring salad dressing over salad bowl

Whether you're enjoying a meal out or eating a delicious homemade sauce, it's a good idea to ask for your dressing or sauce on the side. Unfortunately, many dressings and sauces (especially store-bought ones) are loaded with empty calories, added sugars, saturated fat, and oils that can drastically increase the calorie content of your meal without you even realizing it.

You're not fasting long enough.

intermittent fasting concept, alarm clock on dinner plate

If you've listened to any health-related podcasts in the last few years, you've likely heard of intermittent fasting and its weight loss benefits. According to the Mayo Clinic, intermittent fasting involves cycling between periods of eating and fasting. For instance, you may decide to eat as you normally do, but restrict that eating time to a specific eight-hour window on a daily basis. In that case, you might not have breakfast, eat your lunch at 12 p.m., and then savor dinner by 8 p.m. There's also "alternate-day fasting," which is a form of intermittent fasting that calls for following your typical diet one day and then fasting or consuming a tiny meal that's fewer than 500 calories the following day.

Adam Meyer
Adam is a health writer, certified holistic nutritionist, and 100% plant-based athlete. Read more about Adam
Sources referenced in this article
  1. Source:
  2. Source:
  3. Source:
  4. Source:
  5. Source:
  6. Source:
  7. Source:
  8. Source:
  9. Source:
  10. Source:
  11. Source:
  12. Source:
  13. Source: