Fitness: Why can’t I lose weight?

Craig Nolan is a Maricopa resident and a member of the Exercise Science faculty at Mesa Community College.

By Craig Nolan

This is a common question asked by many people who commit to an exercise program, dietary restriction program, or a combination of both.

The answer seems simple: If I expend more calories than I take in I will lose weight. Many people who have lost weight through exercise alone, diet alone, or a combination have been successful. But there are people, and I will bet you know some, that have tried exercise and dieting and have not been successful or as successful as others.

It begs the question, “Why are some people successful at weight loss and others not so successful if they follow the same exercise program and/or diet?”

There are a number of influential factors that can affect the ability of an individual to optimally lose body fat. I will touch on some of the more common reasons as to why some of our bodies seem to want to hold on to that stubborn fat.

Genetics – Overweight teens have a 70-percent chance of becoming overweight adults; this probability increases to 80 percnet if one parent or both parents are overweight or obese (U.S. Department of Health and Human Services 2007).

Some scientists believe our genes will determine our ability or lack of ability to optimally shed those stubborn, unwanted pounds.

Resting Metabolic Rate (RMR) – This term is defined as the energy required to maintain essential physiological processes in a relaxed, awake, and reclined state. A low RMR can be detrimental to a weight loss program. RMR is highly regulated by the thyroid hormones most specifically thyroxine. If an individual is lacking a specific production of the thyroxine hormone it can reduce RMR by 30 to 50 percent.

Stress – When an individual is under an excessive amount of stress it can make losing weight more difficult. Excessive stress signals the adrenal glands to release cortisol, which is classified as a stress hormone. Studies have shown that excessive stress and cortisol levels can lead to excessive fat accumulation in the abdominal area. Fat in this area is highly correlated with heart disease and strokes.

Lack of sleep – The National Sleep Foundation (NSF) recommends younger adults (18-25) and adults (26-64) acquire at least 7 to 9 hours of sleep per night. Studies show that inadequate sleep and sleeping disorders can have adverse effects on a person’s appetite.

Leptin, an appetite suppressing hormone, will decrease in people that are sleep-deprived. Sleep-deprived people are more likely to consume foods that will spike their insulin levels to try and increase their energy levels in order to make it through the day.

There can be many other reasons as to why people struggle to lose those unwanted pounds.

Three out of the four factors that I have discussed can be improved through positive lifestyle changes. RMR can be increased by engaging in regular resistance training exercise. Stress can be alleviated by allocating time in the day for diaphragmatic breathing or meditation. Sleep can be improved by adhering to a regular sleep cycle.

If you’re not willing to adopt these new lifestyle changes and would rather pin the blame on someone else, look no farther than Mom and Dad. The genes that were passed onto you from them are highly influential in determining your body type.

Obesity and sleep. (2016). Retrieved March 31st, 2016, from
Advanced Fitness Assessment and Exercise Prescription: 6th ed. (2010). Champaign, IL: Human Kinetics.
Murray, R., & Kenney, W. L. (n.d.). Practical Guide to Exercise Physiology. (2010). Champaign, IL: Human Kinetics.

Craig Nolan is a Maricopa resident and a member of the Exercise Science faculty at Mesa Community College.


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