Weight loss Is Only Half The Battle

I am not going to lie, losing weight is a difficult task. In fact, it’s probably one of the hardest things you will ever have to do. Why? Simply because it requires lots of discipline and lots of changes you may never have had to make before. The truth is, if you are wanting to improve your body composition, strip away the excess pounds and show that hard earned muscle, then it’s going to be a necessary evil. There is no way around it. If you are trying to lose weight for the first time, then it’s going to bring quite a shock to your system as you adjust to new ways of thinking about and approaching your nutrition. It might sound all bad, but as you start to see the body you have always wanted in the mirror, trust me, the motivation pushes you through and the process becomes much, much easier. All it takes with fat loss is small changes in body composition to elicit big motivational drives.  

But losing weight is really only half the battle. Most of the time, advice is given on how to lose body fat, but very rarely does this advice deal with maintaining the end result. Yes, you can meet your weightloss goals, but what then? The game doesn’t stop there! You need to think about how you go about maintaining what you have achieved and the approach you will take to prevent possible relapses (e.g. weight re-gain, slipping back into previous, bad nutritional habits). Dealing with the problem is a start, but keeping the problem permanently at bay, is the real challenge. 

So two important questions to ask then are:

What are the possible mechanisms that might cause individuals to re-gain the weight they have lost?

What tactics can be employed to prevent weight re-gain after the initial weightloss period?

The Energy Gap Concept

In a review paper by Melby et al (2017), an interesting concept was proposed that might help explain why some individuals re-gain weight lost after a weight loss period. This was termed the energy gap concept. Essentially, this concept highlights the metabolic changes that take place during weight loss, and how subsequently these changes can drive post-weight loss individuals to re-gain the weight back. According to the energy gap concept, when an individual restricts their calories and loses weight, there is a discordance between appetite and energy requirements, hence the term ‘energy gap’.

Basically, after weight loss an energy gap arises because there are an increase in hunger signals and a reduction in energy expenditures. What happens as a result of this energy gap? Simple evolutionary survival biology kicks in! The body tries to get you to re-gain this lost weight back by increasing the level of hunger you experience and reducing your energy expenditure. The net result is that your body will desire more calories. It’s this desire that usually leads many to re-gain the weight.

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Melby et al (2017). Figures shows the ‘energy gap’ that can occur during weight loss maintenance. After weight loss there is an increase in hunger, reduction in satiety and a reduction in energy expenditures. This can lead to an energy gap as the body tries to gain the lost weight back (through increasing the desire to eat). 

What Factors Cause Individuals To Consume More Calories? (Hunger And Satiety)

Rise in Ghrelin (an orexigenic hormone) concentrations. Ghrelin is implicated in increasing hunger levels and reducing satiety. Ghrelin rises when calorie intake drops and stay high during a maintenance period of reduced weight. 

There is a reduction in anorexigenic peptides (such as peptide YY, amylin, cholecystokinin, pancreatic polypeptide and glucagon-like peptide 1). In the fed state, rises in these anorexigenic peptides lead to termination of food intake and increased satiety. However, during calorie restriction these peptides decline (and is usually greater than the decline in bodyweight itself). This can lead to a strong metabolic milieu which promotes weight re-gain following weightloss. 

During weightloss there is a reduction in fat free mass (FFM). Melby et al (2017) highlight that losses in FFM during weightloss can stimulate the drive to eat in order to restore this lost FFM, through increased hunger and reduced energy expenditure. 

What Factors Cause Individuals To Consume More Calories? (Reduced Energy Expenditure)

Weight loss results in a reduction in total daily energy expenditure (TDEE). The TDEE is made up of resting metabolic rate (RMR), physical activity energy expenditure (PAEE), which consists of non-exercise activity thermogenesis (NEAT) and exercise energy expenditure (ExEE) and thermic effect of food (TEF). 

During weightloss there is a reduction RMR. RMR is essentially the energy your body needs to power all of its cellular processes (to keep you alive!). A reduction in RMR can occur through loss in respiring FFM (it uses energy, e.g. muscles). A reduction in RMR (independently of FFM reductions) can also occur through increased adaptive thermogenesis (AT). AT is basically changes in energy expenditure independent of changes in FFM and the composition of FFM. Increased AT can occur through lower circulating levels of leptin, insulin and tri-iodothyronine and decreases in sympathetic nervous system activity.

There is also a reduction in PAEE. PAEE is made up of non-exercise activity thermogenesis (NEAT) and exercise energy expenditure (ExEE). Both are reduced as a result of weightloss. The loss of body mass from weightloss can mean that fewer calories are expended during similar weight bearing activities (as before weightloss). After weightloss, there is an increase in energy efficiency by skeletal muscle during low intensity activities (e.g. daily living activities, low exercise workloads), which can contribute to reductions in PAEE and ExEE. The mechanism for these effects might come through reduced levels of leptin in response to weight loss.

There is also a reduction in energy expenditure through food digestion (TEF). With lower quantities of food ingested during weightloss, there will be less energy expended due to lower levels of digestion. Hence a lower TEF. 

Can We Attenuate This Weight Re-Gain? 

A Review Of Possible Strategies By Melby et al. (2017)

Melby et al (2017) highlight a number of useful strategies that could be highly beneficial in helping individuals prevent re-gain of their weight after they have lost it. Essentially, the task will be to increase levels of satiety, reduce hunger and prevent reductions in TDEE after a period of weightloss. Really, it’s ensuring that people don’t feel the need to eat more when they try to maintain a new target weight, because trust me, your body will fight you back!

•Diet Composition• 

A diet which effectively reduces the energy gap by increasing levels of satiety and limiting hunger levels could be an effective method of preventing weight re-gain and enhancing weightloss maintenance in individuals. Given that protein exhibits stronger effects on satiety and higher thermic effects following consumption (than carbohydrates and fats), higher protein diets are likely to provide higher levels of satiation and less reduction in energy expenditures. Making weight loss maintenance more effective. 

Another tactic would be to consider the glycemic index of foods (glycemic index is essentially the ability of foods to raise blood glucose levels following ingestion). Lower glycemic foods will include things like vegetables, whole fruits and legumes and lean meats. Lower glycemic foods have been found to lower the energy intake of individuals, reduce hunger levels and attenuate the reductions in RMR and TDEE following weightloss. 

Higher fibre containing foods have been found to improve weight control and lower food intake. Since higher fibre foods take longer to digest, the increased digestion time is likely to allow longer for the release of anorexigenic peptides (resulting in earlier meal termination, increased levels of satiety and reduced hunger). The lower energy density of higher fibre foods is also likely to constrain overall energy intake. Taken together, higher fibre foods are likely to enhance weight loss maintenance by reducing energy intake and increasing the release of peptides implicated in reduced hunger, increased satiety and earlier food termination. 

•Energy Expenditures•

It has been suggested that increasing activity levels significantly might help to increase the chances of weightloss maintenance success. Higher levels of exercise are likely to attenuate the reductions in RMR (especially through increased resistance training), NEAT and ExEE. Given that the amount of activity one will do following weight loss will be less (e.g. increased metabolic efficiencies at lower work intensities), then initiating exercise programs (e.g. high-intensity cardio) and increasing general activities such as walking, taking stairs, less time sitting etc. will help attenuate the decreases in NEAT and ExEE. 

Increasing TEF through ensuring a diet high in protein. Since protein is highly inefficient at being digested, the body will expend a lot more calories (in comparison to carbohydrates and fats) to digest it. Combined with calorie reduction + high protein diet’s, the reduced energy intake + TEF will help aid in weightloss maintenance. 

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Melby et al (2017). Figure shows the possible methods of reducing the energy gap to enhance weight loss maintenance success. Through increasing the proportion of high-protein, high fibre and low glycemic index foods in your nutrition plan, this can help to reduce overall energy intake, increase energy expenditures, release of anorexigenic peptides, reduce hunger signals and increase satiety. All making weight loss maintenance much more successful over the long-term.   

The Energy Flux Problem

Two of the major problems many people are faced with in todays society is an abundance of food (e.g. cheap, accessible) combined with highly sedentary lifestyles (e.g. office jobs, less manual labor). While many might succeed in losing weight, these daily lifestyle pressures can really make it impossible for some to maintain their weightloss efforts. So, how exactly do you combat this weight loss maintenance problem? Well firstly let’s be realistic, the way society is set up nowadays, it’s not going to change overnight. I can safely say that I don’t think we are ever going back to hunter-gather times, that is over. But, that doesn’t mean all hope is lost! The solution is simply to consider the ‘energy flux problem’.

What is the energy flux problem? Simply put, there are two energy flux’s: high-energy flux and a low-energy flux. High-energy flux is characterised by high-energy expenditures and matched with high-energy intakes. The low-energy flux is characterised by low-energy expenditures and matched with low-energy intakes. Now, in most cases it’s pretty easy to maintain a current weight target if you have a higher physical job (or do tons of exercise!). This increased energy expenditure has to be matched with higher energy intakes if you are to maintain a specific weight target. The good thing is, in this state of high-energy flux, you are not competing against these societal pressures. Not to mention, as pointed out by Melby et al (2017) the higher energy-intakes generally lead to less hunger, and attenuation of the energy gap. But, take the low-energy flux, if you are pretty inactive then the only way of maintaining of weight target is if your energy-intake is also lower. Not impossible to do, but in light of today’s societies pressures, it seems pretty unlikely for most (especially if you were previously overweight or obese). 

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Melby et al (2017). Figure shows two energy-flux states. The high-energy flux state is characterised by high energy expenditures, matched with high energy intakes. While the low-energy flux state is characterised by low energy expenditures, matched with low energy intakes. The high-energy flux state might actually be the best approach to enhancing weight loss maintenance success (given today’s societal pressures – abundance of food + sedentary lifestyles). 

It’s likely then that the best way of combating weightloss maintenance problems in light of today’s society is to move individuals towards higher energy-flux states. Increasing their physical activity to a point so that higher energy-intakes are a must to maintain their weight loss maintenance targets. Not only that, but as Melby et al. (2017) highlight, increased activity is likely to not only increase energy expenditures, but also regulate the release of anorexigenic peptides, suppress appetite, enhance ones sensitivity to insulin and leptin and enhance satiety signals. Together, these benefits of a higher-energy flux state would help to reduce the energy gap that occurs during weight loss maintenance. It seems then that the best approach is to combine high levels of exercise and high-energy intakes in order to enhance weight loss maintenance. 

To Sum Up

Weight loss maintenance is difficult due to an energy gap that arises (increased hunger and reduced energy expenditures). This increases the drive to eat and re-gain the weight back.

High protein, high-fibre and low-glycemic foods might be able to enhance the success of weightloss maintenance period through reducing energy intakes, increasing the release of anorexigenic peptides, reduces hunger signals, increases satiety and increases TEF

Massively increasing exercise will help to boost TDEE making weightloss much more manageable

Higher-energy flux’s (higher energy expenditures matched with higher-energy intakes) are likely to be more successful in maintenance of weight loss over low-energy flux states. Simply because it avoids the pressures of todays society (increased food abundance + increased sedentary lifestyles). 


Any questions, ask away!