dieting and still gaining weight

Reasons You are Gaining Weight Even in a Calorie Deficit

If you are gaining weight even in a calorie deficit, it can be SO frustrating. A “calorie deficit” is when a person burns more calories than they consume. This can lead to weight loss, but not always!

Weight loss is not as simple as calories in versus calories out. There are other factors that could be causing weight gain despite a calorie deficit. Often we need to address these other factors in order to reach a weight loss goal.

7 Reasons You Might Be Gaining Weight In A Calorie Deficit

1. Hormones

Hormones control many of the body’s processes, including metabolism. So if hormones are not in balance, metabolism might slow down.

Key Hormones to Consider


Cortisol is commonly known as the stress hormone because it controls your body’s stress response. It also has the job of regulating metabolism, inflammation and immune function, including blood pressure maintenance and blood sugar regulation.

When cortisol is released, it raises blood pressure and blood sugar, which in short bouts is okay. However, If this occurs more often, then it can have a negative impact on health. Cortisol triggers the body to release stored glucose into your blood stream. Therefore frequent high levels of cortisol can lead to elevated blood sugars (hyperglycemia). This leads to the body releasing more insulin to regulate this, putting your body into a state of inflammation.

If you think that you have chronic stress, then it is important to get your cortisol levels tested. Normal levels are 6 to 23 mcg/dl ( micrograms per deciliter). Levels will change throughout your day, so cortisol is usually tested in the morning, when levels are highest.


Insulin’s plays a huge roll in metabolism in many different ways, such as:

  • Glucose metabolism
  • Glycogen metabolism
  • Lipid metabolism
  • Protein metabolism

Consistently elevated levels of insulin in your blood stream can lead weight gain from your body storing the excess sugar it produces.


Leptin is the hormone that is released by adipose (fatty) tissue, which helps you maintain your normal body weight. This hormone also aids in controlling your appetite by signaling when you are full, which is key to maintaining a proper calorie balance.

Your leptin level is known to be proportional to your level of body fat. When you begin to lose weight, specifically fat mass, your leptin level will decrease as well. This can make it more difficult to feel satisfied, which can lead to eating too much.

Thyroid hormones

Thyroid hormones directly control your metabolism. The two main hormones are Triiodothyronine (T3) and thyroxine (T4). These both play a major role in weight regulation, as they affect how you burn energy. If these hormones are not within the normal ranges, this can impact weight loss.

Signs that something may be off

Some signs and symptoms of a hormone imbalance can include but are not limited to:

irritabilityhigh stressincreased heart rate
thinning of hairincreased urinationincreased thirst
darkening of skin around neckthinning of hairincreased hunger
skin tagselevated blood pressureweight gain

What to do if you think your hormones are off

If you feel like your hormones are not in balance, reach out to your primary care doctor and share your concerns. They will hopefully order labs, which can provide insight into any hormonal factors that are a road block to weight loss.

Also schedule a visit with one of our Registered Dietitians, who can create a custom weight loss plan just for YOU that takes into account your age, any issues revealed by your labs, activity level, lifestyle etc. This plan will include 1:1 nutritional counseling, as well as nutrition education and supplement guidance.

When it comes to hormone imbalance, a doctor or dietitian might suggestion supplements that are helpful. Vitamins and minerals that are known to help with hormonal imbalance include the following:

  • Myo-inositol
  • Omega-3 fatty acids
  • Vitamin D (You can order a Vitamin D test here to learn more about your levels)
  • Selenium
  • Zinc
  • Turmeric
  • Ashwaganda

Without proper guidance, supplements can lead to health issues. Therefore consult with your doctor or your dietitian before taking them. Once you speak with a medical professional, visit our supplement store to order.

2. Decreased Basal Metabolic Rate (BMR)

Your BMR is the rate at which your body uses energy while at rest to keep you alive (i.e., your basic functions such as breathing and digestion). A lower BMR means that you are not burning as many calories while at rest. If your body is not burning as many calories while at rest, then you could easily be over estimating your caloric needs, and not truly be in a caloric deficit. 

A few factors that can cause your metabolic rate to be slowed include:

Increased levels of stress

As explained earlier, the stress hormone cortisol directly affects your metabolism. It can elevate your blood pressure, slow digestion, cause muscle pain and tension, decrease quality of sleep and much more. Managing your stress is therefore imperative. Helpful ways to manage stress include exercise, therapy, meditation, journaling, breath work and supplementation.

Lack of adequate sleep

Lack of sleep is another reason why you may not be losing weight in a calorie deficit. As mentioned earlier, lack of sleep can cause disruptions in hormones, especially those that regulate your appetite (namely ghrelin and leptin) as well as cortisol, the stress hormone that can slow your metabolism. Lack of sleep can also negatively affect your decision-making skills, which can make it challenging to keep track of calories, and limit your ability to make informed nutrition decisions.

Ways you can improve your sleep include establishing a bedtime routine that allows for 7-9 hours of sleep nightly, and limiting screen time before bed. If there are any other sleep disturbances, then it is important to reach out to a sleep expert.

Extreme restrictive caloric intake

When you begin a VERY restrictive diet, your body might be unable to meet the energy needs of your basic functions, such as digestion and respiration. When you factor in all of the other activities you do on a daily basis, from brushing your teeth to walking around, then your body is shorted even further. Your body can begin to slow itself down, burning less energy in order to preserve functioning at all cost.

Imagine this scenario:

Before you jump into a caloric deficit, you are eating regularly and fueling your body. You may be burning upwards of 1,500 calories per day. But after jumping into a very restrictive caloric diet, you may only be burning 800-900 calories per day. This is significant!

Reminder that the definition of VERY restrictive is individualized, as everyone has their own energy needs. Ask your dietitian what your needs look like, and find out whether you might be over-restricting.

Hormonal imbalance

As explained earlier, proper functioning of your hormones matters! The imbalance of cortisol, insulin, leptin and/or your thyroid hormones can directly impact your basal metabolic rate and impact how much energy you are burning on a regular basis.

How to increase your BMR

Way you can increase your basal metabolic rate include:

  1. Eating enough calories
  2. Balancing your caloric intake properly between carbs, fat and protein
  3. Increasing your water intake
  4. Managing your stress in a healthy manner: counseling, exercise, meditation etc.
  5. Exercising

3. Decreased Muscle Mass

Your body composition may be another reason why you are still gaining weight while in a calorie deficit. If you have a higher body fat percentage and lower muscle mass, then you are probably burning fewer calories than if you had more muscle mass. Muscle mass increases your metabolism, since it takes more energy to build and maintain muscle than it does fat mass.

How to increase your muscle mass

  1. Eat the appropriate ratio of protein, carbs and fat
  2. Focus on strength endurance and max strength training.

Ask your dietitian or personal trainer how to achieve these goals!

4. Overestimating Calories Burned from Physical Activity

Your level of activity, specifically overestimating the calories burned through exercise, may be another reason why you are not meeting your weight loss goals. Overestimating the calories burned could easily put you in a calorie surplus without you even realizing it. 

Also, the type of exercise you are doing may not increase muscle mass. Adding muscle mass helps improve metabolism and also helps the body burn calories more efficiently.

5. Underestimating Caloric Intake

Being in a true caloric deficit can be hard to accomplish and often, calories are not tracked precisely. Meanwhile, precision is key to proper calorie tracking! You should not just track what you eat, but you should also be aware of proper portion size. Learn to read labels, and measure and weigh foods for a clear picture of your true caloric intake.

This takes time, knowledge, and discipline as well as consistency and can be quite challenging. That’s why underestimating caloric intake is often a primary factor in why people struggle to lose weight.

6. Age

Your age needs to be considered as well. As you get older, your muscle mass decreases, which can slow your metabolism. You might also experience a decrease in appetite, which can cause you to eat too few calories, which can also lead to a slower metabolism. Lastly, your mobility may be limited, which can cause too little energy expenditure. So if you are aging (which we all are), then you need to pay closer attention to these factors. 

7. Alcohol Intake

Alcohol is a macronutrient that some of us forget to include when evaluating our diet. It contains seven calories per gram. It provides energy, but it can also cause low blood sugar, low testosterone, increased estrogen, and fluid and fat retention.

The impulse to reach for foods generally increases upon impairment from alcohol. To compound this, having low blood sugar can also lead you to consume carbs or other fast foods in order to regulate your blood sugar levels. This addition of extra calories from food and alcohol can easily put you over your limit.

Additionally, low testosterone caused by alcohol consumption can lead to decreased muscle mass, which as we mentioned above will decrease your BMR.

In Summary

You now know all the factors that may be causing you to gain weight while in a calorie deficit. The next step is to identify the ones that apply to you! Consider scheduling an appointment with a Registered Dietitian Nutritionist, who can evaluate the many factors involved in weight loss, and create a custom weight loss plan just for you.

Our Registered Dietitian Nutritionists (RDNs) will work with you to create realistic and customized goals to ensure long-lasting results. We use small changes so that weight loss occurs naturally. Learn how nutrition and movement can be just as powerful as medication and surgery for weight loss!