How to Break Through a Weight Loss Plateau
Updated: Sep 9, 2022
What is a Weight Loss Plateau?
So you’ve decided to lose weight. Everything starts well. You’ve found a plan that works for you and things don’t seem too difficult. The scales gradually ticks down and you feel you’ve got this.
Until one morning, you step on and there’s been no change. No worries you think, its just one day. But this turns into 2, then 3 and before you know it a whole week has gone by with no change.
Alongside this you notice your new routine is getting harder to follow. You feel drained, it’s becoming harder to resist food and your family comment that you’re not your usual happy self.
So what’s going on here? Welcome to the weight loss plateau! A place almost anyone who has tried to lose weight has found themselves in.
In this article we’ll explore the reasons you may find yourself in a weight loss plateau and what you can do to manage it.
Understanding some key elements about human energy expenditure will help us master this topic. Let’s start by quickly examining how we estimate human energy expenditure.
Many of you are likely familiar with the wide range of calorie calculators that can be found online. Typically, these ask for your age, gender, height, weight and physical activity level. They can then use this information to estimate your Total Daily Energy Expenditure (TDEE).
These calculators are based on a variety of studies that measured peoples energy usage at rest. The studies found that it is our lean body or fat free mass, so our organs and muscles, that contribute the most to our energy use throughout the day.
Our TDEE can be subdivided into the following categories to give us a better idea of how we are using energy:
Basal Metabolic Rate (BMR) is the energy expenditure of an individual lying at physical and mental rest in a thermoneutral environment, at least twelve hours after their last meal. BMR supports breathing, circulating blood, organ functions, and basic neurological functions. It is proportional to lean body mass and decreases approximately 0.01 kcal/min for each 1% increase in body fatness. This can make up about 40-70% of our TDEE.
Secondly, we have Non-Exercise Activity Thermogenesis (NEAT). NEAT includes the energy used for things like standing, fidgeting, blinking and moving about. This can make up about 15% of our TDEE.
Next we have the Thermic Effect of Food (TEF). This represents the energy cost of chewing, swallowing, digesting, absorbing and storing food. This will vary depending on the amount and types of food we consume. While the thermic effect of protein, carbs and fats in isolation differ, the thermic effect for a mixed meal is about 10%, and it does not tend to vary much under conditions of energy deprivation.
Finally we have Exercise Activity Thermogenesis (EAT). This is the energy we expend when undertaking periods of voluntary exercise such as sports and fitness activities. For most people this only accounts for 5% of their TDEE, but can vary significantly between individuals depending on their activity levels.
How Do We Lose Weight?
When starting a diet we will intentionally reduce our energy intake from food below our estimated requirements in order to create a deficit. This forces our body to use its stored energy, which includes glycogen and fat.
Glycogen stores are limited and last only a few hours depending on activity level. They help maintain our blood glucose levels throughout the day and night.
On the other hand, fat is very energy dense so a little can go a long way. Just 1kg of body fat contains about 9000kcal.
If we maintain a deficit for long enough our body will rely on these energy stores resulting in weight loss. Although very simple in principle, many people find they are unable to lose weight beyond a certain point.
Why Do We Reach a Weight Loss Plateau?
There are a few different reasons people can find themselves reaching a weight loss plateau. Let’s explore a few of these now:
1. Human Recall
Firstly, it is important to acknowledge that people will often underestimate how much food they have eaten and overestimate how active they have been throughout the day.
For those who have reached a weight loss plateau, this may simply mean that your current intake now matches your requirements, despite feeling like you have made significant changes.
For most people, the evidence suggests, this is likely to be the main reason they have reached a weight loss plateau.
However, there are a number of behavioural and physiological changes that can take place within the body that may also explain this problem.
2. Behavioural Adaption
When in a prolonged energy deficit people exhibit increased food seeking behaviour and are more likely to choose higher calorie options when given the choice.
This may explain why food is always on your mind when following a diet and certain foods become harder to say no to.
The subconscious drive to seek out higher calorie foods was likely very important during human evolution. This system worked really well when we lived in a feast-famine society, when there was not always a guarantee of that next meal. However, in today’s feast-feast society this behaviour has become problematic.
3. Reduced Body Weight and Lower Energy Requirements
We now know that our energy requirements are based our weight, or more specifically our fat free mass.
As we loose weight a certain percentage will also come from our lean body mass. This is normal. As we get lighter we don’t need as much muscle to help move ourselves around. This will have caused a reduction in our energy requirements.
For example, we may go on a diet that is 100kcal less than our requirements and lose 10% of our starting weight. At this new lower weight we might need 100kcal less per day to cover our TDEE due to a reduction in our fat free mass.
Our body is now operating at its new lower requirements and we would naturally not expect any further weight loss. This is why we need to periodically reduce our calorie intake to continue losing weight over longer time periods.
4. Reduced Thermic Effect of Food
You may also have spotted earlier that part of our TDEE goes to digesting the food we eat.
If we have reduced our food intake by going on a diet we will have also slightly reduced our bodies energy requirements to digest this food.
This is only going to be a small change in our TDEE, but when comes to weight loss small amounts can mean the difference between being in a deficit and a surplus.
Being aware of this effect will help us calculate if we are in a deficit or not.
5. Adaptive Thermogenesis
So in principle weight loss should be fairly straight forward. If we reduce our energy intake below that of our TDEE, we create a deficit. When in an energy deficit our body will utilise its energy stores, resulting in weight loss.
However, this statement is based on the principle that calories in and calories out are two independent variables that are not interlinked. Unfortunately, this is not the case. What actually happens is a little more complicated.
Our bodies have the ability to regulate their energy use. This means that if we consume less energy our bodies can choose to use les energy, either partially or completely negating the deficit we are trying to create.
We call this effect adaptive thermogenesis. Adaptive thermogenesis is likely a survival mechanism that served us very well during our evolution, especially when humans experienced periods of food shortage.
Sadly, this mechanism is unable to account for today’s modern food environment and can make maintaining a healthy weight very difficult for some.
What Is Adaptive Thermogenesis?
To understand this mechanism we need to first acknowledge that when all other things are equal a person with a larger body will require more energy than a person with a smaller body.
Adaptive thermogenesis describes a change in TDEE, during periods of energy deficit, that is greater than what we would expect based on changes in body weight alone. In essence, the body has become more conservative with energy expenditure.
The point at which adaptive thermogenesis starts can vary between individuals, with some seeing its effects very quickly after implementing an energy deficit, whilst others may not see anything until losing a certain amount of weight.
In addition, some people may experience greater amounts of adaptive thermogenesis than others. Those who have been observed to have larger reductions in TDEE, beyond that anticipated, also experienced a larger increase in their desire to eat.
Adaptive thermogenesis may go part of the way to explaining why it is more difficult for some people to lose weight and keep it off than others.
Let’s take a look at how adaptive thermogenesis works.
Adaptive Thermogenesis & Physical Activity (PA)
The largest effect of adaptive thermogenesis is seen in a reduction of our NEAT. As we discovered earlier, NEAT can make up 15% of our TDEE.
It appears that our bodies’ capacity to reduce NEAT is linear, meaning that as more weight is lost NEAT levels can continue to drop. This drop is subconscious, and will include a reduction in things like walking, standing, typing and even fidgeting.
Adaptive Thermogenesis can also lead to a reduction in the intensity of any EAT. You may experience this by feeling like you aren’t able to give the same intensity when exercising, or that you are far less inclined to exercise in the first place.
Adaptive Thermogenesis & BMR
Interestingly, our bodies are also able to down regulate our BMR in repose to an energy deficit. Unlike PA there is a limit to how much this can happen, as this is the energy our body uses for essential processes.
Diet induced changes in BMR may be compounded by increased EAT, as it is not uncommon to try and increase your exercise when on a diet.
This fits in with the constrained energy expenditure model, which proposes that as individuals increase their EAT, their body can partially compensate by reducing BMR.
Although this reduction in BMR is only likely to partially compensate for the increased EAT, this can lead to discrepancies in estimated TDEE, leaving people feeling frustrated at their rate of weight loss.
This effect was observed when Kevin Hall analysed the BMR of contestants from the Biggest Loser TV show and found those with the greatest persistent metabolic adaption had maintained a high level of physical activity since the competition.
Ageing can also affect our response to a weight-loss intervention, as it is associated with a greater-than-predicted decrease in BMR. This may partly explain why people find it harder to lose weight as they get older.
What Can We Do?
Evidence shows that if we can sustain a large enough deficit below our requirements we will lose weight.
As we have just discussed, the first step to overcoming a weight loss plateau is to accurately record your energy intake and expenditure. This will help you identify the most suitable areas to focus on.
If you’re tracking your food intake, make sure you track everything! Also consider your eating habits over the long term. Weight loss does not depend on having mostly good days, but rather being consistent with your eating plan over long periods of time.
What If You Are Experiencing Adaptive Thermogenesis?
As we have learnt, our bodies are very adept as preserving energy. Understanding what we can and can’t control is the next step in this process.
There is little we can do about the reduction in our BMR and TEF. However, we can ensure an accurate base line by frequently reassessing our energy needs in response to any weight loss.
Thankfully, we do have some degree of conscious control over our physical activity. You may find it helpful to track your NEAT with a step counter before going on a weight loss journey. Once you have implemented an energy deficit try to maintain your current activity levels throughout the day. The goal is to prevent any unconscious reduction that may occur.
For those who can, walking is a very underrated activity that allows us to increase our physical activity throughout the day.
Current recommendations suggest aiming for 150 minutes of moderate intensity exercise per week, and including at least 2 sessions of strength training. This is of particular importance during an energy deficit as it will help preserve lean body mass. Maintaining muscle also promotes improved mobility and independence as well as reducing your risk of developing other health conditions.
I would encourage you to find activities you enjoy and can see your self sticking with long-term.
There are still questions whether the changes we see with adaptive thermogenesis persist over time. Studies of people who have undergone bariatric surgery did find patients’ BMR returned to normal once they were weight stable.
Another study that examined participants from The Biggest Loser TV show found they still had a decreased BMR many years later. However, this is thought to be due to some of the contestants maintaining a significantly higher physical activity level.
When we combine the natural human tendency to under report our food intake, which only needs to be off by a small amount, and our ability to adapt to a reduced energy intake we create the perfect conditions for a weight loss plateau.
When setting the goal of weight loss I would encourage you to aim for sustainable changes that increase the healthfulness of your diet, as opposed to implementing significant short term deficits as many fad diets do.
If your diet does not feel sustainable, it is very likely that when yous stop following it any weight lost will return. Our weight is determined by our long term dietary and lifestyle choices, not brief phases of dieting.
This is not to say strict dieting regimes will not work, but in these cases particular attention needs to be payed to any food reintroduction phases to ensure this is appropriate for your new lower weight.
What About The Rate Of Weight Loss?
General guidance is to avoid cutting too quickly. However, this may depend on your starting point.
For relatively lean individuals, looking to improve body fat levels for sports or competitions, a dramatic reduction in calories may be more likely to result in greater loses of fat free mass.
However, for those with a higher starting body fat a larger deficit can be an effective way to promote weight loss at a rate that provides increased motivation.
The current evidence suggests adaptive thermogenesis seems to occur due to the amount of weight lost and not necessarily the rate.
Do keep in mind that chronically eating less than 800kcal per day may put you at increased risk of nutrient deficiency. This is why any Very Low Calorie Diet (VLCD) interventions are only ever recommended for a maximum of 12 weeks.
If implementing a deficit it may be helpful to ensure you still consume sufficient protein, as this will go some of the way to mitigating losses of lean body mass.
Find a coach and community
Finally, if you're struggling I would encourage you to ask for support. Sometimes getting an outside perspective on things can make all the difference. A weight loss coach can guide you through difficulties, provide accountability and increase your chances of maintaining your weight loss long-term.
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