Why It Is Hard To Maintain Weight Loss | Weight Regain Explained
In three decades of helping men and women of all ages lose weight, the most common frustration is the ease with which their weight loss efforts can be undone if they stray too far off the path of healthy eating and I am often asked why is it so hard to maintain weight loss. Regaining weight after dieting is one of the most difficult experiences for those trying to lose weight, even among those who exercise regularly and are strict with their diets. Yet, for so many, putting the pounds back on over time seems to be almost inevitable. There are two ways the cycle of weight regain usually plays out. The first is behavioral. A slip brought on by being too goal oriented and you can read more about this in my article How Goal Setting Reverses Weight Loss. The second, and perhaps most insidious way that weight regain occurs is biological in nature, which is what we are going to focus on in this article and also explore what you can do to stop the numbers on the scale from slowly creeping back upwards when you are trying to lose weight. Thanks as always for reading and do be sure to share this article with anyone whom you think might find it to be of interest.
You do everything “right”! Training regularly, counting calories, avoiding junk food and you are rewarded by losing some weight, but one day it all stops. The numbers on the scale simply won’t go any lower, and worst of all, you begin to find it harder and harder to maintain your weight loss. Weight regain occurs, slowly, but steadily despite redoubling your efforts in the gym. You start spending more time in the gym, but while initially it was working, it now all seems to be for nothing. Exasperation starts setting in and you being to consider giving up. You tell yourself it’s so hard to maintain your weight loss that you may as well go off your diet as you aren’t making any progress anyway. Things start spiraling out of control. Suddenly you find yourself struggling to get back on track with your diet, as the foods you were easily avoiding before now seem to be irresistible. Most will see this as some form of a moral failing, lack of willpower, or even some genetic curse that prevents you from keeping the weight off, but as badly as you might feel, it’s important to bear in mind that it isn’t really your fault. Nor is it anything about your particular genetic makeup that’s stopping you from maintaining your weight loss. It’s simply how the human body works and this scenario plays out at one point or another for most people, whether you are overweight or an ultra-lean fitness model. Regardless of your weight loss goal, the average experience using conventional methods of training and dieting will almost inevitably be an initial loss of weight that slowly grinds to a halt over time. Then weight loss reverses with a gradual increase in weight. Weight regain that continues despite increased efforts to restrict calories and increased exercise volume, but as we will see, even doubling the amount of cardio you do won’t make a difference. Here’s why and it’s an immutable fact based on evolutionary biology:
The prime directive of the human body is to ensure your immediate survival in the event of lowered energy availability by holding on to as much accumulated body fat as possible. The human body evolved over millions of years in an environment where it was always lean and with relatively low bodyfat. As such, it is not designed to lose body fat and keep it off.
While today most of the globe is obsessed with weight loss, this desire goes against your body’s evolution-based design to conserve energy by any means necessary. When you make the decision to reduce your energy intake and increase your activity level, it is done with a feeling that we are completely the captains of our ships and in control of what will happen next, whereas truth be told, most of us don’t have as much control over our weight loss as we would like to think. Your body simply CANNOT distinguish between the threat of starvation and your desire to shed a few pounds to look better by cutting your calories and exercising more and it makes sense if you put it in context. Imagine one of our ancestors several hundred thousand years ago subsisting completely in a natural environment. Now in that environment, bereft of supermarkets, all the food consumed comes from either hunting and or gathering, which requires a significant amount of energy. In this natural environment, a reduction in energy means a reduction in food supply, and that you will have to hunter more and gather more to compensate. And so your body needs two things to happen.
- It needs to conserve energy as much as possible so you don’t lose any more vital body fat, so you will have enough energy reserves to allow you to keep on looking for food and
- It needs to force you to get up and get going to try and get as much food as possible by stimulating your appetite.
The bodies we inhabit today are the same ones our ancestors had all those hundreds of thousands of years ago, and so your body has no way of knowing that access to food is not the same as it was in a natural hunting and gathering environment, and that you are voluntarily CHOOSING to limit your energy intake and increase your activity levels. No one in a natural environment would ever have thought to do this and so your body exerts tremendously powerful physical and neuroendocrine changes that promote weight regain after a certain amount of weight loss. Makes sense when it’s spelled out that way, but still some might think that we can just use willpower to overcome these drives. The truth is that very few of us can, and these mechanisms are powerful enough that large and long-term studies show that 30% to 35% of weight lost by men and women trying to lose weight is regained within a year. 50% of participants will return to their starting weight within five years of their initial weight loss, regardless of the dietary or behavior intervention model used. Only 1 in 6 overweight or obese men and women report being able to hold on to just 10% of their weight loss for a year at any given point in their lives. As conventional diet, exercise and clinical interventions have not yet shown an effectiveness in treating either severe obesity or unwanted weight gain in general population long term.
The problem of regaining weight so easily after losing it is perhaps one of the most complex issues that most of us will face over the course of our lives. The media and most fitness related information typically waters down the complexities of sustainable weight loss into manageable sound bites to keep their audience engaged or (most commonly) as a vehicle to sell products and services. However, such an approach does little more than make weight loss even more confusing for those trying to make sense of why keeping the weight off is just so darned hard. I will say that in 30 years of helping clients lose weight and keep it off, that there is no one magic answer that fits everyone, but it possible. It isn’t easy, but it starts with an understanding of the very real and complex challenges you face when trying to lose weight, and I hope this article helps empower you if you too are struggling with regaining weight.
Why It Is Hard To Maintain Weight Loss: Understanding Energy Expenditure
The Chinese philosopher Sun Tzu wrote that if you know your enemy and know yourself you will be victorious in every battle, and in the battle to maintain weight loss it’s just as important. We understand now why our bodies don’t want us to lose weight and keep it off, and now we delve into an understanding of the mechanisms of how our bodies make us regain lost weight. It starts with some familiarity with how our bodies expend energy and there are two factors to consider, namely Resting Metabolic Rate (RMR) and Total Energy Expenditure (TEE)
Resting Metabolic Rate, (a term often interchanged with Resting Energy Expenditure), accounts for approximately 60% of your total daily energy expenditure and it is by far the largest and most important component when it comes to why your body loses or gains weight.[1,5,9] Resting Energy Expenditure is defined as the energy needed to fuel the minimal daily functions of organs and cells [42,43] and it varies based on how much lean muscle mass you are carrying, and to a lesser degree, thyroid related hormones and protein behaviors.
The second component of energy expenditure, is Total Energy Expenditure, (TEE), which represents a compilation of the many ways that our body burns calories, and it includes resting metabolic rate, diet induced thermogenesis, and activity related expenditure.[3,4] Now we would assume that this figure would fluctuate widely among different populations, as it takes into consideration energy expended during activity. And for a very long time it was thought that an athlete or someone engaged in large amounts of manual labor would logically have a higher TEE than a sedentary individual. However, in keeping with the evolutionary model we introduced earlier, calorimetry research has shown that while our bodies may burn more calories during a period of activity, it might also trigger a response whereas Resting Metabolic Rate decreases in order to compensate for the increased energy output. Remember our bodies are still stuck in the Neolithic Era and it is trying to do everything possible to help you keep on looking for food without burning too many calories, as that would make the very act of looking for food enough to hasten starvation. This is why just being more active, especially doing steady state aerobic activity, doesn’t neatly equate losing more weight or keeping it off long term.
Why It Is Hard To Maintain Weight Loss – Why Being Bigger Means Burning More Calories
I did say it was a complicated subject and in today’s environment when being overweight is not just a possibility, but a reality for many, it creates some other problems when we try to shed extra pounds and keep them off. Larger men and women are often told that they have a harder time losing weight because they have a slower metabolism. However, this is absolutely not the case as the mechanics are such that the absolute energy expenditures of individuals who are obese or overweight will always be higher than that of someone of a lower bodyweight while at rest. Two important factors account for this phenomenon:
- Individuals who are obese tend to have higher fat free mass than those who are not and thus have a higher resting energy expenditure. [5,6]
- Larger bodies require more energy to move and thus expend more calories in physical movement and thus have a higher total energy expenditure.
If you stop and think about it, it’s rudimentary Newtonian physics, as a larger body would obviously requires more energy to move and operate than a smaller one. The reason daily recommended energy intakes for men are usually higher than they are for women is because men on average burn more calories than women do because they usually have higher body weights and more lean muscle mass. This relationship between body weight and energy expenditure is one of the reasons why endurance athletes like cyclists and marathon runners try to shed every excess pound so as to expend less energy and be more efficient during their events. The differences are notable. A typical 190 lb. man on average burns 1,380 kilocalories per hour running at a fairly rapid pace of 11 miles per hour, while a 130lb man burns only 828 kilocalories per hour. That’s 40% less energy expenditure while running at the same pace. This reduction in Total Energy Expenditure as body weight decreases is relatively straightforward.
Why It Is Hard To Maintain Weight Loss: How Extreme Caloric Restriction Can Slows Down Your Metabolism
Weight loss means a decrease in fat mass and fat free mass (muscle) and since both forms of tissue are metabolically active, (fat free mass especially so), weight loss inevitably leads to a reduction in Resting Metabolic Rate. Since RMR counts for such a large percentage of energy expended in the body, this decrease is thought to be one of the primary causes of weight gain after weight loss. The concept of weight loss leading to a decrease in energy expenditure is known as “adaptive thermogenesis.” Which served us so well during our time in a natural environment to be able to survive periods of low food availability, but in today’s world, it leads to the vicious cycle of weight gain that happens after weight loss. A cycle that continues not out of any lack of willpower or hard work, but because the amount of calories you are consuming to lose weight will inevitably become more than what your body needs to sustain that weight reduced body weight. Which then creates a positive energy balance of more calories coming in than going out, (even though you are dieting) and this, over time, leads to weight gain.
Why It Is Hard To Maintain Weight Loss: The Lingering Metabolic Effects of Extreme Diet & Overtraining
One of the problems with decreased Resting Energy Expenditure after weight loss is that it can take a long amount of time for your metabolism to go back to what it was before you lost weight. And in some cases, the change is permanent. The Prevention of Obesity Using Novel Dietary Strategies (POUNDS LOST) study looked at over 800 overweight or obese men and women to compare the effects of four different diets on weight loss. Researchers observed that six months into the dieting phase, Resting Energy Expenditure decreased significantly with weight loss and it took on average a total of two years for it to return to baseline levels.
A study of overweight men and women undergoing massive weight loss during the popular weight loss television reality series, The Biggest Loser further highlights the role that lowered Resting Energy Expenditure can play. Seven significantly overweight males and three females were trained under supervised conditions for an average of two hours a day, six days a week for thirty weeks doing a combination of aerobics and circuit training. Dietary intake was at least 70% of baseline energy requirements and after thirty weeks, participants lost between 127 lbs. and 52 lbs. An extreme reduction to say the least, as some subjects lost as much as 40% of their initial body weight. This weight loss came at a price though, as fat free muscle mass accounted for approximately 17% of the total weight lost. Concordant with a drop in muscle mass, resting metabolic rates plummeted from baseline figures by about 350 kcal per day after the first 6 weeks and went down to a low of 790 kcal per day.
Putting this into perspective, a reduction of almost 800 kcal per day would mean contestants would need to eat at least two whole meals less than what they started to maintain their weight loss. As bad as this may have been, the true damage was revealed years later when six men and eight women, who were all former contestants on the show, went to the National Institutes of Health for follow-up measurements. As would be expected, all but one had regained most of the weight lost but shockingly, the group as a whole on average burned 2,607 kcals per day at rest before the competition, which dropped to about 2,000 kcals per day at the end of their time on the television show. Six years later however, their resting metabolic rate had slowed down even further to 1,900 kcals per day,  which is a bit of a puzzle since their body composition and weight returned to baseline levels. What this means is not only does our body reduce energy consumption in response to extreme energy reduction and over exercising, but it does so long term. From an evolutionary perspective, it makes perfect sense as the body perceives a real end of the world scenario when food intake drops and exercise levels become extreme, as it thinks you are spending all that time trying to find food, and so to protect you, it makes your body do more with less.
Why It Is Hard To Maintain Weight Loss: The Problem With Sudden Drops In Energy Intake
Fat free (muscle) mass is the most metabolically active form of tissue in the body and uses more energy than any other form of body tissue. As such, it would stand to reason that those who lose weight through interventions involving exercise that increases muscle mass would have a higher resting energy expenditure than those who lost weight without training as in the example of someone undergoing bariatric surgery. However, when the contestants of the Biggest Loser were compared with men and women who had bariatric surgery, their resting energy expenditure was LESS than those who had surgery, even though they preserved and (built to some degree) far more muscle mass during their weight loss than those undergoing surgery. Most importantly, both groups experienced decreases in resting metabolic rates that were out of proportion to the decreases in their fat mass and lean muscle mass.
Contrary to popular beliefs that muscle mass offsets any reduction in resting metabolic rates, we have seen from the examples above that fat free mass preservation did not stop the reduction of metabolic rate and consequent weight regain. Such findings coincide with my personal observations over the past few decades working with some male and female bodybuilders, figure and bikini competitors who all had far above average muscle mass, yet struggled to lose weight even when caloric intake is at 70% or less of their estimated total energy expenditure. In each case, the athlete came to me after years of excessive contest preparations that included extreme caloric restriction coupled with weight training and cardio, sometimes as often as twice a day, six days a week.
Why It Is Hard To Maintain Weight Loss: Females Tend To Have A Harsher Rebound From Extreme Dieting Compared to Males
In my experience, female athletes seem especially prone to very significant weight regain after periods of excessive caloric restriction, coupled with excessive amounts of weight training and cardio. A common approach that is not too far removed from the over training prescribed for subjects of the Biggest Loser study. I see this as well with women who underwent some form of extreme dieting at some point in their past, and long term studies of women who lost weight and regained it without large prescriptions of exercise or overly severe dietary practices do not find the same discrepancies with lowered resting metabolic rates that are out of sync with their body composition after weight loss. In common parlance it’s termed “metabolic damage” and while it’s a clear metabolic adaptation to extreme weight loss in some individuals, we don’t exactly understand all the mechanisms behind these adaptations. Researchers did observe that this metabolic slowdown correlated directly with changes in circulating leptin, which is a hormone released from fat cells that send signals to a part of the brain called the hypothalamus helps regulate and alter long-term food intake and energy expenditure. And research has found a connection between leptin levels and the degree of average energy deficit in the subjects studied. Decreases in circulating thyroid hormones have also been found, which may account for the noticeable number of female figure, bodybuilding and bikini athletes with thyroid problems. Among those with out of sync metabolic rates there is also blunted activity of the sympathetic nervous system and it could be a combination of all of these factors that lead to reduced resting metabolic rates. [53,54,55,56,57,58,59]
Such findings should be a stern warning against the employment of very excessively low calorie diets in conjunction with extreme exercise volume that would create massive energy deficits and trigger the aforementioned metabolic slowdown.
Regaining Weight After Dieting: How Protein & Carbohydrate Intake Affects Weight Regain
So we can clearly see what we should not do and now the focus becomes what SHOULD we be doing to reduce body fat and prevent metabolic slowdowns and weight regain. Many studies confirm that a high protein, low to moderate carbohydrate diet can be effective for short term weight loss, [24,25,26] and there is sufficient evidence for the recommendation of a high protein diet with low glycemic index carbohydrates for weight maintenance after dieting.  (Read my article: Understanding Glycemic Index for more information about low glycemic index carbohydrate choices) Why is a high protein diet so important for maintaining weight loss? In order for our bodies to digest the foods that we eat, a certain amount of energy must be used to break down the component of our food in digestion, a process referred to as diet induced thermogenesis. Diet induced thermogenesis accounts for about 10% of total energy expenditure. The different macronutrients, protein, fats and carbohydrates all stimulate oxygen consumption differently, meaning they all require differing amounts of energy to be broken down, with protein requiring the most energy for oxidation. A factor which may influence weight loss and weight regain. In general, dietary protein requires 20 to 30% of its usable energy to be broken down into amino acids that can be used and stored in your body. Carbohydrates on the other hand require only 5 to 10% of its total caloric value to be broken down into usable sugars, and dietary fats require as little as just 3% of its total energy value to be broken down into usable fatty acids and glycerol.  As such, dietary protein intake consistently elicits a greater after meal thermic effect of food than fats or carbohydrates.[34,35,61]
High protein foods also help preserve lean muscle mass while dieting [9,28] in addition to promoting higher satiety levels after eating them, which can limit excessive calorie intake. [36,37,38,39] (See my article How Much Protein Do You Need for more information on how protein helps preserve muscle mass while dieting. There are two aspects of the effects of proteins effects on appetite. First, there may be a protein-specific appetite cues that regulate your intake so that you are consuming enough dietary protein to meet your body’s needs. Second, dietary protein has stronger effect on making you feel satisfied after eating than dietary fats or carbohydrates [62,63] which may lead to reductions in daily overall energy intake and prevent weight regain. [64, 65]
Given that fat free muscle mass uses more energy than any other tissue in the body and that higher protein intakes are associated with greater muscle mass preservation during periods of energy restriction, it does make sense to follow a high protein diet to maintain weight loss. However, you don’t need the enormous bro-science amounts suggested in many bodybuilding circles of 1 gram per pound of bodyweight, (which is 1 gram per 2.2 kilograms for those who use metric), as such high intakes have never been clinically proven to be necessary.[30,31,32] (For more information on protein intake during fat loss see my article on Protein Intake Here).
During energy restriction and weight loss, researchers believe that there is a shift in metabolism, where fat oxidation becomes favored over carbohydrates as the body’s main source of energy. During weight regain however, a metabolic reversal occurs, and carbohydrates seems to be become the main fuel source as fat stores are preserved. [28,29] So a diet that isn’t high in carbohydrates can be an important factor if you have lost weight and are trying to maintain it, as the lowered carbohydrate intake may prevent weight regain by blocking this reversal.
Why It Is Hard To Maintain Weight Loss: The Strategy of Increasing Muscle Mass & High Intensity Training
Less extreme and closer to standard weight loss protocols don’t fare much better for weight loss as well, as those using hypocalorie diets alone average a decrease of 25% of fat free muscle mass. While the authors of the Biggest Loser study saw a muscle mass reduction of 17% as relatively small amount, if you understand the role played by muscle mass in keeping your resting metabolic rate high, it’s hard to agree with them. And it’s clear to see that the loss of so much muscle would make weight regain almost inevitable without continued extreme interventions. Other weight loss interventions such as bariatric surgery also bring about undesirable reductions in fat free muscle mass that result in slower overall metabolism and a high likelihood of weight regain over time.[12,13,14] Such findings might lead us to throw out hands in the air and conclude that significant long term weight loss is unrealistic and that the weight will always come back. However, this is far from being true, as conventional approaches to weight loss have two inherent flaws. The first is that in the quest to produce rapid results in the way of lowering body fat, the evolutionary biology of how our bodies are designed to stop and reverse weight loss in the event of lowered energy intakes is ignored. And secondly, the focus is in the wrong direction as it should not be squarely centered around interventions to lower body fat but rather focused on methods to increase muscle mass!
The most important part of any sustainable weight loss program is cannot be focused on creating an energy deficit through high volume training, cardiovascular exercise and lower calories, as we know it is only a short term solution that leads to long term problems. Instead the onus must be on INCREASING and or preserving muscle mass at all cost. Increasing muscle mass means higher resting metabolic rates, which allows for energy intakes to remain within more practical limits for the average member of the population. (See my article on The Evolutionary Argument For Eating More To Lose Weight) Several reputable studies confirm the role of resistance training in preserving muscle mass during diet induced weight [24,25,26,27] and it is an approach that I have used in my own practice for the past thirty years. If resting metabolic rates account for 75% of daily energy expenditure and is determined mostly by fat free muscle mass, it stands to reason that trying to lose weight by employing practices that decrease muscle mass will inevitably be counterproductive.
So in a nutshell, here is the most efficient and tried and tested way to lose weight and keep it off long term:
- Since increases in fat free muscle mass from weight training lead to higher resting metabolic rates, weight training must be a part of the protocol.[9,27]
- Intensity in resistance training is directly proportional to the “afterburn effect” or excess post exercise oxygen consumption (EPOC) which is the increase in energy utilization to bring the body back to homeostasis and repair damaged muscle tissue after training. And so a high intensity protocol is recommended as it can, in conjunction with the increase in muscle mass it creates, help gradually decrease body fat levels if dietary intake is sufficient. [22,23]
- Consume a high protein diet that is not overly hypocaloric, with adequate, but not excessive amounts of high fiber, unprocessed carbohydrate sources so as to support muscle growth and preserve existing muscle mass while keeping energy intake at moderate levels. [27, 28,30]
Aerobic Exercise Vs Resistance Exercise For Long Term Weight Loss
Skepticism has always existed regarding the use of muscle building exercise as a protocol for weight loss, as aerobic exercise is typically associated with losing body fat, even though numerous studies find high intensity weight training as being more efficient than conventional aerobic exercise for reductions in fat mass.[22,23] Aerobic exercise can indeed reduce fat mass, but has little effect if any on the preservation of fat free mass. [29,30,31] Not only does this increase the possibility of weight regain, but from a cosmetic point of view, diet induced weight loss using such forms of exercise would result in a smaller, but still flabby version of what you started out with if resistance exercise is not included in your regime. There is a slight increase in calorie expenditure for 20-48 hours after aerobic exercise, but only if such exercise is done with sufficient intensity and relatively long duration.[32,33,34,35] Except for this small window, there is, however, no increase in resting metabolic rate regardless of how much aerobics you do. On the other hand, increases in fat free muscle mass permanently increase resting metabolic rates, and the so called after burn effect of high intensity training from excess post exercise oxygen consumption is also greater than that of aerobic exercise.[22,23]
Practical & Sustainable Solutions Through Resistance Exercise & High Protein Diet
In my own practice over the course of thirty years, I have records of thirty one significantly overweight individuals who lost over 50lbs using only a combination of high intensity weight training done just three times a week for no more than ten minutes a session with no cardio whatsoever. Protein intake was always kept high, carbohydrate intake never dropped low enough for ketosis to occur and calorie intake was not overly restrictive as emphasis was always on long term adherence, muscle growth and preservation as opposed to simply inducing negative energy balance. Notably among those thirty-one trainees, eight of them lost over 100 lbs, weight loss comparable with some of the numbers cited in the Biggest Loser study. However, the process was centered on lifestyle change, took far longer, average of 12-14 months, and did not involve more than thirty minutes of high intensity training per week. Unconventional, to say the least, but it’s an effective program founded on the science of maximizing resting metabolic rates, diet induced thermogenesis and absolute energy expenditure in a practical and sustainable manner. Most importantly increased muscle mass over time limited weight regain, as only 10 out of 31 trainees regaining more than 70% of the weight lost after a year. And most importantly 20 of them were able to maintain 10% or more of the weight lost five years after their weight intervention with me. A success rate significantly higher than 35 to 80% found in studies who regain all their weight loss within 1 year.
Now such a small sample size of men and women who paid a significant amount of money to change their lives might fall into the category of the error of small numbers and as such no be applicable to the general population. But having worked with literally thousands of men and women at this point of a career that has spanned three decades, and saw me work with clients either in person or online of in just about every country on the planet, it’s hard to argue with a system that sees an average weight loss of 12-23 lbs that persists for a year or more among a group that numbers 742. A sample size that is large enough to call for more research in the use of brief high intensity resistance training without any cardio and a muscle building focused diet as a long term weight loss tool.
Reduction in body fat through high intensity weight training does not yield the quick decreases on the scale that would be seen from high volume aerobic exercise and low calorie diets- which in itself is a good thing as you don’t lose muscle mass in the process. However it does provide a long term solution for those needing to lose weight with the added benefits of increased strength and improved self-esteem thanks to increased lean muscle mass. Muscle mass that is key to the development of the lean, toned and tight body that is without question the Holy Grail of our time. A look that is unattainable from high levels of aerobics and or low calorie intakes, as such activities have little effect on the increased development of skeletal muscle and from what we know can predispose you to regaining the weight you worked so hard to lose.
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