Why Am I Not Losing Weight? 11 Common Exercise and Diet Mistakes, According to Experts

Wondering why you’re not losing weight when you’ve been exercising more than ever and overhauled your diet? This could be down to some of the common diet and exercise mistakes people make while trying to lose pounds.

It’s important to bear in mind that a weight loss plan is different for each individual, so what works for some, may not work for you, Roxana Ehsani (RoxanaEhsani.com), a Registered Dietitian Nutritionist (RDN) and national media spokesperson for the Academy of Nutrition and Dietetics, told Newsweek.

“Each person has a unique lifestyle, with varying abilities, needs, and goals. Therefore, exercise programs should be designed specifically for each individual,” Roger Franco, an assistant fitness manager at Crunch Fitness Fort Greene in New York City, told Newsweek.

Below experts explain some of the common exercise and diet mistakes for weight loss.

Why Am I Working Out but Not Losing Weight?

Eating too much after exercise

Dr. Keri Denay, a fellow with the American College of Sports Medicine (ACSM) and team physician for U.S. Figure Skating, told Newsweek that one of the biggest mistakes people make when trying to lose weight is assuming they can eat more because they’re exercising more.

“If a person’s goal is to lose weight by incorporating more physical activity, the individual’s caloric intake would need to remain the same as prior to initiating the increase in exercise or decreasing the amount,” she said.

Skipping resistance training

Macklin Guzmán, the Chief Science Officer for the Medi-Weightloss program who is also an epidemiologist and clinical scientist, told Newsweek that doing hours of cardiovascular exercises but skipping resistance training is among the most common mistakes made.

A woman looking at a treadmill dashboard.
A woman looking at the dashboard of a treadmill. Exercise and diet go hand-in-hand when it comes to weight loss.
iStock/Getty Images Plus

Strength training can help you conserve lean muscle mass which has higher energy expenditure than fat, helping you to not only lose weight but keep it off. While cardio exercises burn more calories than strength training, your metabolism stays revved up for longer after lifting weights than after a cardio workout.

“Getting it right means doing a combination of both cardio (high intensity) and resistance training to obtain the heart benefits of cardio and the positive metabolic effects of strength training. A combination of both is the ideal exercise program for improving health and body composition,” he said.

Why Am I Losing Inches but Not Weight?

When this scenario occurs, it’s likely that you’re losing body water (initially) and body fat (eventually), while also building muscle,” Denay explained.

“These changes may result in some degree of body shape change,” such as a smaller waistline, even if your weight on a scale overall hasn’t changed that much, she said.

Ehsani agreed. If you’re struggling to lose weight despite diet adjustments and exercise, “it could be that your body weight maybe hasn’t changed but your body composition has changed in a more positive direction, such as less body fat, but more lean muscle mass,” she said.

Do a DEXA (Dual-energy X-ray) scan to check your total weight, body fat percentage, lean muscle mass percentage as well as bone health, the RDN advised.

A person holding tape measure at waist.
A person wearing oversized jeans, holding a tape measure around their waist. Losing inches in your body does not necessarily mean you are also losing weight.
iStock/Getty Images Plus

Why Am I Not Losing Weight in a Calorie Deficit?

Extreme dieting

Sports nutritionist and registered dietitian (RD) Nancy Clark told Newsweek in many cases people “diet too hard”, which results in them being hungry and overeating, which is “a physiological response to having gotten too hungry.”

They “hold off” to have a nice dinner but “that is counter to circadian rhythms, as well as sets the stage for having gotten too hungry and overeating,” she said.

When we drastically cut down calories, our bodies adapt to such food scarcities by conserving energy. This means our metabolism slows and movement is reduced, while our appetite increases.

Instead of cutting calorie intake, you’ll want to “frontload your calories,” Clark said, noting “as one client said [to me] ‘When I ate dinner for breakfast and breakfast for dinner, I lost weight so easily…seemed like my fat just melted away.'”

While reducing calorie consumption is the most common weight loss strategy, to change body composition and reduce body weight, you need to analyze the nutritional value of each food item, according to Franco.

“For example, foods may have the same caloric index but highly different nutritional values,” he said.

Foods with good nutritional value (such as vegetables as well as lean meat) and a low glycemic index can help “increase lean muscle, improve overall strength and increase
caloric expenditure through exercise,” Franco explained.

Portion control

Research has shown that when offered larger portions, “people tend to consistently eat more food than they normally would,” Guzmán said. So portion size plays a significant role in weight loss.

There are several strategies that can help control portions, from using smaller plates for meals at home, “since smaller dishes hold less food and you will be less inclined to over portion on a larger plate,” to requesting a smaller portion at a restaurant and asking them to pack the rest away for you take home, he explained.

Not tracking your calories accurately or at all

Keeping a food journal is another key tool that’s overlooked by dieters, Guzmán noted, that can track your calorie intake, types of foods consumed as well as portions. Journaling allows people to “become more self-aware of the dietary patterns that may have led them to increased weight in the first place,” he said.

There are plenty of apps that allow you to scan your food and provide the nutritional values such as calories and macronutrients (protein, carbohydrates and fats). Weigh your food on first entry to ensure the data is accurate. You may find you are consuming more than the recommended serving and therefore are no longer in a calorie deficit.

Other Reasons You’re Not Losing Weight

Avoiding fruit and vegetables

Guzmán said how many calories you consume is just as important as the type of calories you consume, as there are a lot of hidden calories in certain types of foods, for example, “two hundred calories of spinach are not necessarily the same as two hundred calories of cookies,” he explained.

Often what most Americans are lacking in their diet are fruits and vegetables. “Fruits and veggies are our lowest calorie food, so if your goal is to lose a few pounds, adding more fruits and veggies into your meals and snacks can help you get there,” Ehsani said.

Fruits and vegetables are also loaded with the vitamins, minerals, dietary fiber, antioxidants and nutrients we need to promote overall health.

Not eating enough carbohydrates

Carbohydrates tend to be among the first foods people cut out when trying to lose weight. But if you’re actively exercising and under-eating carbohydrates, you’ll notice a decrease in energy and performance. “That’s because carbohydrates are the preferred source of fuel that your brain and muscle need each and every day to function,” Ehsani said.

“Being properly fueled with enough carbohydrates will give you the energy to train longer and harder and ultimately lose weight,” she explained.

Slices of whole wheat bread.
Slices of whole wheat bread. Carbohydrates are essential source of fuel for your brain and muscles.
iStock/Getty Images Plus

Protein overload

Many times people consume a lot of protein instead of carbohydrates in an effort to gain muscle. But eating too much of it will not help you lose weight, as it will be stored as fat. The protein overload will also be taxing on your kidneys and may cause constipation, Ehsani warned.

Not cutting down processed foods

The rise in obesity in America “correlates well” with the increased intake of ultra-processed foods, warned Clark. So you need to “fret less about sugar/carbs, and more about the processing” and find time to prepare proper meals instead.

A woman eating a bowl of salad.
A woman eating a salad at a table spread of fruits and vegetables. Eating more fruits and vegetables is a key part of weight loss.
iStock/Getty Images Plus

Inadequate Sleep

Ehsani explained research has found that those who are sleep deprived are more likely to choose unhealthier food choices than when they’re properly rested.

“Lack of sleep can alter our stress, hunger and appetite hormones,” the RDN said. During the day, you’re more likely to eat more overall to help stay awake, potentially snacking more often and reaching for more sugary or caffeinated beverages.

Not managing stress

Your stress levels could be sabotaging your goals for losing weight. “When our stress hormone—cortisol—is constantly being activated and is high, it may cause you to gain weight too,” Ehsani said. Stress reduction techniques, such as deep breathing, meditation and yoga, can help calm down these stress hormones.

A man stressed, sitting at a desk.
A man sitting at a work desk, looking stressed with a hand on his face. Stress levels can sabotage your weight loss goals.
iStock/Getty Images Plus