Obesity poses significant health risks, including cardiovascular disease and cancer. Unfortunately, many weight loss strategies fail to deliver lasting results; participants often regain the lost weight, sometimes even more.
Dr. Layne Norton explained why this happens and shared actionable strategies for sustainable weight loss.
Obesity Risks
Excess adipose tissue, or obesity, significantly raises the risk of type 2 diabetes, cardiovascular disease, cancer, and overall mortality. “Those risks hold even when you correct for other variables,” Dr. Norton noted.
Being healthy doesn’t require having a shredded physique. Research indicates that a body fat percentage of 15% to 20% is perfectly healthy for men. “That’s not shredded. That’s kind of like your dad bod,” Norton described. A healthy body fat percentage for women typically falls between 20% and 30%.
Individuals who maintain a lean physique often face real-life challenges, such as hormonal imbalances, reduced testosterone, and mood swings.
False Information Around Fat Loss
Today, individuals encounter various challenges when managing and navigating information. “Over 87% of social media fitness claims are false,” Dr. Norton stated. Even when some of these claims are true, many are focused on things that don’t matter.
Social media is flooded with weight loss content, but research reveals that people are more influenced by celebrity appeal than expert advice. “They found that celebrities and politicians will get far more influence over people’s decision-making than actual subject matter experts,” Dr. Norton pointed out.
Fat Loss Problems
While weight loss is a common challenge in society, an equally significant issue lies in maintaining that weight loss. Many individuals with obesity successfully shed a substantial amount of weight at some point in their lives, but the majority eventually regain it. This often happens because sustaining the habits and lifestyle changes that led to weight loss proves difficult over time.
Moreover, your biology does work against you. There is a biological drive to regain pre-diet weight, sometimes more.
—Dr. Layne Norton
Calorie Deficit
The key to weight loss is creating a calorie deficit — burning more calories than you consume. This principle is essential for shedding pounds.
Upon reaching goal weight, the focus shifts to maintenance, which involves balancing calorie intake with energy expenditure to sustain progress. “If you exceed that over time, you will regain weight,” Dr. Norton explained.

Calories represent the potential energy stored in food’s chemical bonds. Through metabolism, the body releases and transfers this energy, primarily by producing ATP (adenosine triphosphate).
During this process, ATP molecules lose a phosphate group to form ADP (adenosine diphosphate), a highly energy-efficient reaction that powers many essential, energy-demanding processes in the body.
When you consume more energy than your body needs, the excess chemical energy from food is processed through a series of reactions and ultimately stored as fat in adipose tissue.
Conversely, when there is an energy deficit, the body taps into its fat reserves, breaking down stored energy in adipose tissue to fuel bodily functions and maintain metabolic processes.
Consistency and Weight Loss
Maintaining a steady calorie balance is essential for preventing weight gain. How does one improve consistency, and what factors contribute to better adherence?
Self-efficacy
This requires a deep, personal drive and intrinsic motivation to lose weight. It’s about fostering an internal commitment to changing one’s current weight.
Social Support
Various types of social support can significantly aid in weight loss. Having a gym buddy, participating in group fitness classes, or working with an accountability partner are all effective strategies.
Moreover, identifying with a specific dietary community can enhance success, as individuals who build a sense of identity and connection within a group often demonstrate greater commitment and consistency.
Greater Initial Weight Loss
Early weight loss success can inspire and motivate individuals to stay committed to their weight loss journey.
Tailoring Diet to Individual Preferences
Individuals who started with a diet resembling the fat loss plan demonstrated higher adherence levels. Dietary swaps to reduce calorie intake can significantly support fat loss efforts.
Increasing Protein & Fiber Intake
High-protein diets are known for their higher adherence rates, while fiber-rich foods have been shown to enhance feelings of fullness and satisfaction. (1)
Food Monitoring & Measuring
What gets measured, especially when it comes to food, gets managed. Regularly weighing yourself can promote weight loss by fostering more mindful and intentional eating habits. (2)
Energy Balance
Energy balance is the relationship between the calories consumed and those burned through activity and bodily functions. However, not all consumed calories are metabolized. Specific non-digestible food components contain calories the body cannot convert into usable energy. “Your metabolizable energy is the amount of calories you take in minus whatever you lose in your stool, essentially,” Dr. Norton explained.
Energy expenditure, or “energy out,” is a more complex concept than it might seem. It refers to total energy expenditure (TEE), which is composed of:
- Resting energy expenditure (REE), the energy the body uses to maintain basic functions at rest, accounts for roughly 50–70% of TEE.
- Thermic effect of food (TEF) represents the energy required for digesting, absorbing, and metabolizing nutrients, which makes up about five to 10% of total energy expenditure.
- Physical activity plays a significant role, divided into two categories:
- Structured exercise
- Non-exercise activity thermogenesis (NEAT) includes all unconscious, everyday movements and non-purposeful activities. Together, these components determine how much energy your body uses daily.
Not Believing Calorie Deficits Work
Dr. Norton highlights that numerous factors can impact the outcomes of a calorie deficit.
Tracking Errors
The majority of obese individuals tend to underestimate their calorie intake by 53% while overestimating their physical activity levels by 47%. “Even dieticians, who are experts at tracking food, under-report by 10% on average,” Dr. Norton disclosed.
Smart Watches and StairMasters often overestimate the number of calories burned during exercise. “These devices, in general, have an error of anywhere from about 30 to 90%. They overestimate calories burned from exercise,” Dr. Norton said.
Sporadic Weigh-Ins
Day-to-day fluctuations in body weight are influenced more by fluid dynamics than by changes in actual tissue mass. “If you want to know if your tissue mass is changing, I recommend weighing yourself daily and then looking at the average for the week,” Norton advised.
Hormones
Hormones influence energy expenditure and appetite, but their effect is less significant than commonly perceived. “Hormones do matter, but a lot of people use them as this blanket scapegoat as to why a diet won’t work for them, and it’s just not true,” Norton said.
Critical Aspects of Weight Loss
Exercise
Exercise is an effective way to burn calories and boost energy expenditure, but its impact is often overestimated. Research on total energy expenditure reveals that physical activity triggers partial compensation through reduced resting energy expenditure and non-exercise activity thermogenesis (NEAT).
In practical terms, if you burn 100 calories through exercise, the net increase in calories burned averages around 72, according to data. While there is still a clear benefit, it’s smaller than many might expect.
There is a constrained energy expenditure model: if you increase exercise, the body will compensate in other ways so as not to burn as many calories.
—Dr. Layne Norton
Exercise regulates appetite by enhancing sensitivity to satiety signals. Sedentary people tend to eat more than those who maintain a moderately active lifestyle.
Exercise’s importance becomes even clearer for weight loss maintenance. Studies show that over 85% of successful weight loss maintainers engage in regular physical activity.
Self Monitoring
A key trait shared by successful weight loss maintainers is the habit of regular self-monitoring. This can include stepping on the scale, tracking meals, or measuring portions — any form of self-monitoring can make a difference.
The act of self-monitoring alone often prompts behavioral changes. Studies show that individuals with obesity who begin weighing themselves regularly tend to lose weight on average.
Macronutrients
While a calorie deficit is the primary driver of fat loss, macronutrients still play an important role. Protein, for example, has a significantly higher thermic effect of food (TEF) than carbohydrates or fats.
Protein’s TEF ranges between 20–30%, meaning that if you consume 100 calories from protein, your body effectively uses 20–30 calories for digestion, leaving you with 70–80 net calories.
In contrast, carbs have a TEF of about 5–10%, resulting in 90–95 net calories per 100 consumed. Fats have the lowest TEF, at just 0–3%, leaving nearly all 97–100 calories available after digestion. This makes protein exceptionally efficient for supporting fat loss in a calorie deficit.
High-protein diets exceeding 1.6 grams per kilogram of body weight have been proven to promote greater fat loss while preserving lean muscle mass compared to diets with lower or moderate protein levels. Regarding carbs and fats, the quality of carbohydrates plays an important role. High-fiber diets, in particular, have been shown to enhance feelings of fullness and satiety, while also naturally reducing overall food intake.
Sleep
Sufficient sleep helps regulate appetite. Sleep deprivation or restriction often leads to increased calorie consumption. Research shows that reducing sleep to two-thirds of normal for just eight days can result in an automatic increase of over 500 calories per day. (3) Inadequate sleep tends to drive more frequent snacking.
Sleep restriction negatively affects calorie intake and impacts the composition of weight loss. Those who don’t get enough sleep are more likely to lose lean muscle mass rather than fat compared to individuals who sleep sufficiently. (4)
While seven hours of sleep is optimal, straying significantly above or below this range can increase mortality risk. (5) Sleeping significantly more than the recommended seven hours can double the risk of early death.
The key to successful weight loss lies in consistency. The best diet for fat loss is the one that an individual can follow and sustain over time.
Any diet is going to have some form of restriction. Whether it’s a dietary restriction like keto or plant-based, it’s a time restriction like intermittent fasting or a calorie tracking restriction, like tracking calories and ensuring you’re in a calorie deficit.”
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References
- Glynn, E. L., Fleming, S. A., Edwards, C. G., Wilson, M. J., Evans, M., & Leidy, H. J. (2022). Consuming a Protein and Fiber-Based Supplement Preload Promotes Weight Loss and Alters Metabolic Markers in Overweight Adults in a 12-Week, Randomized, Double-Blind, Placebo-Controlled Trial. The Journal of nutrition, 152(6), 1415–1425. https://doi.org/10.1093/jn/nxac038
- Steinberg, D. M., Bennett, G. G., Askew, S., & Tate, D. F. (2015). Weighing every day matters: daily weighing improves weight loss and adoption of weight control behaviors. Journal of the Academy of Nutrition and Dietetics, 115(4), 511–518. https://doi.org/10.1016/j.jand.2014.12.011
- Spaeth, A. M., Dinges, D. F., & Goel, N. (2013). Effects of Experimental Sleep Restriction on Weight Gain, Caloric Intake, and Meal Timing in Healthy Adults. Sleep, 36(7), 981–990. https://doi.org/10.5665/sleep.2792
- Wang, X., Sparks, J. R., Bowyer, K. P., & Youngstedt, S. D. (2018). Influence of sleep restriction on weight loss outcomes associated with caloric restriction. Sleep, 41(5), 10.1093/sleep/zsy027. https://doi.org/10.1093/sleep/zsy027
- Burazeri, G., Gofin, J., & Kark, J. D. (2003). Over 8 hours of sleep–marker of increased mortality in Mediterranean population: follow-up population study. Croatian medical journal, 44(2), 193–198.
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