- In a meta-analysis of 29 studies on weight loss, over 50% of the weight initially lost was regained within a two-year period.
- Metabolic adaptations that occur during a diet make regaining weight easy.
- Gradually increasing your calories after finishing a diet can help relieve these adaptations whilst preventing excess weight regain.
- Lifestyle improvements will still probably be necessary to maintain a healthy bodyweight in the long-term.
How many times do we hear the story of someone losing weight only to “gain it all back again”? This is, unfortunately, a common phenomenon. The people to whom this happens are certainly not failures. Indeed, there are a variety of reasons as to why this happens.
Maintaining weight loss: Why it is so difficult?
The obesogenic environment refers to the sum of external influences that facilitate the development of weight gain, leading to obesity. Unfortunately, the modern world makes maintaining a healthy body weight quite the challenge. Whilst frustrating, there is not a great deal we as members of society are able to do about this. Another factor, however, is that many people do not realise that the end of their diet is not in fact a pass to return to normality. Doing so makes weight regain much more likely.
Understanding why weight maintenance is difficult can help you better prepare for these challenges and reduce the likelihood that all the hard work losing weight during dieting ends up going to waste.
- Important note: Weight loss and body transformation should be done with the purpose of moving from an unhealthy to a healthy state. Losing too much weight or chasing unrealistic body standards can also be unhealthy. Your mental well-being should not be dependent on your body image. If you believe you might have an unhealthy relationship with food or your body image, visit your healthcare professional to discuss these issues further.
Dieting: What does it mean?
What constitutes a diet can differ between individuals and professionals. Here, we describe a diet as a temporary period (e.g., 2–6 months) in which someone is trying to lose weight. How one constructs their diet for weight loss is a bit more varied. For example, some may use intermittent fasting or reduce their carbohydrate intake and go “keto”, while others might restrict themselves to whole or natural foods only. Some people may reduce their food intake heavily, while others reduce it only slightly, and so on. The unifying factor in all of these is that the diets aim to cause a reduction in caloric intake, leading to weight loss.
Dieting: During and after weight loss
Many people are aware that with the right dieting and lifestyle changes, you will lose fat and transition to a healthier body state. However, the part that people are less familiar with is what goes on behind the scenes in our body. You may be happy about losing body fat but your body is not. Throughout human evolution, our bodies evolved to perceive fat as a valuable energy reserve that will keep us alive in times of hunger, and because of this, our bodies are not willing to let it go without a fight.
In an attempt to hang on to body fat, our body initiates multiple physiological responses to counteract fat loss.1 These include heightened hunger, reduced satiety, reduced thermogenesis and metabolic activity, energy-sparing mechanisms that make you want to move around less, and with more extreme diets, reduced sexdrive and testosterone, sleep interference, and loss of menstrual cycle in women.1 You may not even notice these responses in the beginning, especially if you have more body fat to lose, however, as you diet for longer and lose more body fat, these will likely become more obvious.
It's these physiological reactions that can make dieting quite unpleasant. In fact, these are also a big reason why many people tend to regain weight after dieting. Indeed, with your new reduced body weight, your body will naturally burn fewer calories throughout the day, reducing the number of calories you can consume without regaining weight. With this in mind, it’s no wonder so many people regain weight after dieting.
- What is a calorie? A calorie is a unit of energy, typically used as a measurement of the amount of energy a food provides, but also used to measure the amount of energy your body uses throughout the day, often referred to as energy expenditure.
Weight management: How to manage your body’s defence mechanisms
Despite these harsh realities, if we know what to expect at the end of a diet then we can think ahead to reduce post-diet weight gain. Just as these adaptations were not there before your diet, they won’t stick around forever either. In order to shake them off, it’s important to let your body believe that you are no longer draining its precious fat.
How do you do this? You can begin to achieve this by slightly increasing your food intake, not quite to pre-diet levels but enough to show your body that it may not need to be so worried about how much fat it's losing. In most cases, a good caloric intake to aim for would be what we call ‘maintenance calories’, which refers to a caloric intake that matches your total daily caloric expenditure, at which you neither gain nor lose weight.2 Your weight might spike a little in the first few days due to the absorption of water by components in your food like fibre and carbohydrates, but this is nothing to worry about. If weight continues to go up, you may want to bring your food intake down slightly until your weight stabilises.
The aim is to continue gradually increasing calories so that your total intake goes up but weight remains roughly the same, eventually reaching a point where calorie intake is sustainable (your maintenance calories) but weight remains lower than before the diet. You may not be able to return to your initial calorie intake pre-diet (especially if this was already too high), but eating in a calorie range that allows you to maintain a healthy body weight is something we all have to deal with. You can, however, make this a lot easier for yourself (see Lifestyle changes below).
The diet after the diet
It might seem disappointing to hear that one of the best solutions to keeping weight off after a diet is to continue dieting, but that’s the reality. Whereas tricksters in the fitness industry and weight loss experts will have you believe otherwise, you typically can’t beat physiology – it will have its way. What you can do, however, is learn to work with it.
In this scenario, working with your physiology might look like this:
- Instead of setting yourself a 10-week diet in which you drastically reduce your calories and lose weight, return to your normal diet, and almost certainly gain all that weight back, try dieting for 16 weeks, with around half of those being in weight loss mode, and half of those being in maintenance and recovery mode.
- This way, you could either work on incorporating lifestyle changes (discussed below) to keep a healthier body weight or possibly give it a few more weeks and go again for another weight loss phase to lose a bit more.
Ultimately, whilst your total time dieting might be longer, you are much more likely to be successful in keeping the weight off. It just takes a little adjustment in expectations.
Tracking calories and weight: Is it for me?
Monitoring your weight and tracking your calorie intake is not for everyone, especially if you have a tendency to become obsessed with the numbers. You can definitely achieve diet success without tracking these elements, it just might be a bit less precise. You can imagine it like driving without a map; you can still get to your destination, you just might get lost a few times along the way.
Knowing your intake and being able to correlate this to your weight changes provides you with objective and extremely useful data which can improve diet success. But if you decide this route is not for you, then make sure to find other ways to keep yourself accountable. This might involve standardising your servings of carbohydrates using different cup sizes or buying products that come with pre-set serving sizes (e.g., bread rolls), etc. Nutritionists typically advise finding ways to do this because our minds are very good at being able to trick us into doing what our bodies might want us to do.
For more information on the pros and cons of tracking food intake, click here
Weight regain: The importance of lifestyle changes
A highly cited meta-analysis (a type of review including many individual studies) in this subject area claimed that around 80% of the weight lost across the 29 studies it included was regained after 5 years.3 Five years is a lot longer than the lengths of time discussed earlier, and physiological changes due to a diet would have reversed since then. So why does weight regain occur then?
The reasons differ between individuals, but a common factor is the obesogenic environment of the modern world which makes keeping a healthy body weight a constant uphill battle.2 Unhealthy and fast foods in abundance make gaining weight all too easy, whereas maintaining a lower body weight requires effort. Gaining weight is painless and happens comfortably, whereas maintaining a healthy weight often requires restraint and discomfort. Hence, even if you finish your diet and successfully keep the weight off within the first year, you might still have work to do to keep your weight within a healthy range.
If you are interested in maintaining a healthy body weight, you might have to accept that you can’t have everything. In the same way that you cannot spend more than you earn every month without accumulating debt, you also cannot eat above your requirements without expecting to gain weight. There are multiple actions you can and should take to help maintain a healthy body weight, backed by decades of research on this subject area.
Prioritise fruit and vegetables
Fruit and vegetables should have gold member status in almost any diet. They have a high volume to calorie ratio (foods that fill you up whilst providing only small amounts of calories). In addition, they also typically contain plenty of fibre which helps with satiety and weight loss, and they also provide you with plenty of vitamins, minerals, and polyphenols, all of which have health benefits.4
Find fruits and vegetables you like and fill your boots with them to help stay fuller whilst reducing calorie intake.
Minimise processed foods
Generally speaking, processed foods tend to have poorer associations with health outcomes, are easier to overeat, and tend not to leave you feeling satiated (feeling full & satisfied).5 There are plenty of exceptions to this, but unless you know what they are, it is advisable to minimise processed foods in your diet.
Aerobic exercise for weight loss and maintenance
Aerobic exercise (or cardio, short for cardiovascular training) refers to training in which the heart rate is elevated for prolonged periods of time, such as running, swimming, cycling, among others.6 Exercising of this kind can potentially increase energy expenditure, whilst also keeping your cardiovascular system healthy.
Resistance training for weight loss and maintenance
Possibly more important than aerobic exercise for maintaining a healthy body weight in the long term is resistance training, i.e., training with weights. Although during exercise, you likely burn less than calories than in aerobic exercise, you are adding muscle and improving body composition in the long term, both of which make it much easier to maintain lower body fat levels.
Skeletal muscles interact with metabolism and bigger, stronger, healthier muscles are associated with reduced mortality and improved overall health.7 Lifting weights also benefits the bones by increasing their density and preventing fractures and frailty. This is especially important with older age.7
The importance of stress reduction and sleep
- Feeling hungrier.
- Feeling less satiated after eating.
- Being more likely to make poorer diet choices.
- A lower likelihood of losing fat and more change of losing muscle when dieting.
- Being less likely to engage in exercise and movement, and a higher change of having poorer training sessions if you do.
The list could go on, but you get the message. Managing stress involves primarily identifying the stressor and either eliminating it, reducing it, or learning to relate to it in a more manageable way, and finding activities to engage in that relieve stress. For sleep, it is crucial to make sure you get enough, both in terms of quantity and quality. It’s very easy to neglect sleep in the modern world with all the stimuli and entertainment we have available, but you will pay the price if you do.
Fortunately, even if you do implement these tips but still end up gaining a little weight over time, now that you know how to diet appropriately, you can just begin a little diet phase from time to time to reduce your body fat and get back a healthier weight. Remember, diets are not a lifetime commitment or an identity you wear; instead, they can just be a tool that we make use of occasionally to keep ourselves healthier. If you need extra support, as many do, it's important to speak to a nutritional professional, one who is registered with recognisied nutrition bodies like the Association for Nutrition or the British Dietetic Association, as examples.
Weight loss and maintenance is difficult
Do not feel disheartened when you realise that losing the weight is only half the battle – this is just an important step in learning how to maintain a healthy body weight in the world we live in. In order to be the healthiest version of ourselves, we might have to adapt parts of our lifestyle. This can be tough, especially in the beginning, but seeing the fruits of your labour come to fruition in the form of a healthier body certainly make it worth it.
- Greenway FL. Int J Obes 2015;39(8):1188–1196.
- Hall KD, Kahan S. Med Clin North Am 2018;102(1):183–197.
- Anderson JW, et al. Am J Clin Nutr 2001;74(5):579–84.
- Slavin JL, Lloyd B. Adv Nutr 2012;3(4):506–516.
- Elizabeth L, et al. Nutrients 2020;12(7):1995.
- Swift DL, et al. Prog Cardiovasc Dis 2014;56(4):441–447.
- Lee DH, Giovannucci EL. Exp Biol Med 2018;243(17-18):1275–1285.
- Papatriantafylloi E, et al. Nutrients 20222;14(8):1549.
- Geiker NRW, et al. Obes Rev 2018;19(1):81–97.