How to Restore a Lowered Metabolism

The term ‘metabolism’ is being used a lot recently by the health and fitness conscious. People are becoming increasingly aware that all their training and nutrition efforts will impact changes not only on the outside but the inside too!

There also appear to be two ‘campuses’ when it comes to our metabolism and the response to different diets, with respect to body composition and health. One side strongly believes that metabolism is the key focal point to a great body and healthy lifestyle. The other believes this to be nonsense, and that good body and health is down to calorie control and macronutrient consideration.

Personally, like the research, I am in the middle of these two campuses, as anyone that claims calories do not matter is missing the bigger picture, and the same goes for those who claim calories are all that matter. Yes, calories and an energy balance are the main mechanism driving weight loss/gain, but there are a range of secondary and tertiary factors that influence energy balance. You can’t tell someone with an eating disorder that ”It’s just calories in vs. out bruh”, could you?

The purpose of this article is to present you with an alternative ‘diet’ which can help you achieve their desired body composition and lifestyle, along with all the necessary steps of how to effectively apply it.

Traditional dieting protocols follow the very basic template of - reduce calories > lose weight > balance the metabolic rate.

In this article, we will look at reversing this process, to create a new dieting formula: balance the metabolism > reduce calories > lose weight > refeed to restore metabolic rate.

What Is Metabolism?

Metabolism can be defined as the sum of the physical and chemical processes that occur in our cells to produce energy.

Essentially, all the catabolic and anabolic reactions in our bodies make up our metabolism. So, when we talk about metabolic repair, what we really mean is fixing our body as a whole unit.

When talking about body composition, we need to look at the energetic aspect of our metabolism (energy burned in a day as calories). This is the amount of energy we use for daily function and is referred to as our metabolic rate. So, remember, metabolic rate = just energy, metabolism = much more than just calories burned.

Our metabolic rate is made up of four different factors, which all need be well defined and understood before progressing into a reverse dieting protocol.

BASAL METABOLIC RATE (BMR) – This is the energy we need to simply fuel our organs and basic physiology. In otherwords, the number of calories you would burn if you were to lie down, completely still for an entire day. This is not to be confused with your resting metabolic rate (RMR) which is your daily expenditure when factoring in movement and activity status.

THERMIC EFFECT OF FOOD (TEF) – This is the amount of energy it costs to break down, digest and absorb food and nutrients in the body. Protein costs the most energy to break down, with approximately 20% of the calories from the nutrient being used to digest it.

NON-EXERCISE ACTIVITY THERMOGENESIS (NEAT) – This is one of the most overlooked yet important factors in determining our metabolic rate. This comprises all activity that is not purposeful exercise (e.g. running, lifting weights, playing a sport). This activity includes sitting upright, standing, walking, fidgeting, chewing and much more.

RESTING METABOLIC RATE (RMR) -  As briefly mentioned above, this is the combined energy it takes for all of the above functions. This is what is referred to as ”Maintenance calories” in nutrition programs.

EAT – This is the purposeful activity that you participate in which includes cardiovascular exercise, weightlifting, playing sports, etc. 

This can vary day to day, but should be factored into your daily energy needs.

What Is Reverse Dieting?

Reverse dieting is an approach that was pioneered by Layne Norton and has been widely  accepted in nutrition communities as a possible method of restoring the significant downregulation of one’s metabolic rate after dieting. However, it is important to understand that it is suitable only for those that have adopted severe diets and experienced significant weight loss accompanied by a loss of energy, fatigue and more.

It is an approach that was first popularized by Norton for bodybuilding athletes that were preparing for competitions. During competition prep, they would need to cut calories severely to shed that last small percentage of body fat. This has been widely shown to spark a downregulation of the body’s output, but also several hormonal changes occur along with other adverse reactions e.g., reduced libido.

Now, because of the reduced output by the body, these individuals actually require much less energy on a daily basis. This can lead to significant weight and fat gain, once they begin to return to their normal diet. Sounds familiar right? Maybe not to the same extent as with bodybuilding athletes, but everyday individuals who have adopted aggressive Calorie-restricted diets will experience this phenomenon to a degree.

So, Norton put forward a reverse dieting protocol for incrementally increasing energy in the diet while reducing physical activity, which if done correctly would help to restore the metabolic rate, while also increasing body fat levels of these competitors. For these athletes, they had reached such a low level of body weight and fat, that some weight gain is desired.

Of course, in everyday individuals, the goal is for minimal fat gain while restoring their metabolic rate to somewhere close to their previous baseline. There are a variety of proposed ways to do this by different sources, but the fundamental steps include –

1. Track your intake – It is first imperative to figure out the energy you’re currently consuming, and the only way to do this is to use a method of food tracking. For 1-2 days eat your habitual diet (the one you’ve been using for fat loss), and track it using a food diary, or more preferably an app e.g. MyFitnessPal

2. Figure out your optimal maintenance needs – This is a very important step. By maintenance here, I mean the energy you need that is based on your weight, height and activity status (don’t factor in the fact that you may have experienced some downregulation here)

3. Calculate the difference – So, if you are following a fat-loss diet, you will be consuming less energy than your maintenance needs. Based on the degree of the deficit, it is now time to strategize how you will start to build back up to this maintenance. Because, chances are, if yu have been following a fat loss diet for some time, your maintenance needs are even lower.

4. Calculate macronutrient ratios – This is another crucial step. If you are following a fat loss diet, you should already be prioritizing protein with an intake of between 0.6 – 0.8 g/lb (1.6 – 1.8 g/kg) of IDEAL body weight. You should not be basing this off your intake, and so it should stay relatively constant throughout the process. 

Next are carbohydrates, which are arguably the most important. Research has shown that by making up the calorie deficit from carbohydrates, assuming protein intake is sufficient, several key hormone levels can be increased such as leptin, thyroid hormone.

Fat should make up the remainder of your energy needs, when protein and carbohydrate intake have been calculated. Fat can also be important for those following low-fat diets, as it is a crucial component for hormone production e.g., estrogen in women

To calculate your optimal needs, check out this free calculator by Legion.

5. Plan the progression – This is where you have flexibility to adjust the approach to your preferences and lifestyle. In short, you need to define the time period and weekly calorie increases that you will use going forward. This should be a slight and gradual increase of 50 – 100 kcals/day every 1-2 weeks until you reach maintenance. NOTE: This does not mean increase intake by an additional 50-100 kCals every day.  Set a daily increased target which you will follow for 1-2 weeks.

6. Return to Baseline – You have reached maintenance, and successfully avoided excessive fat gain throughout the process. You may have gained 1-2lbs, but this is acceptable, as you have most likely brought your metabolic rate somewhere close to your baseline.

If you have achieved your desired weight at this point, then you can continue to consume your maintenance needs until you either want to reduce fat mass further or begin to experience weight gain. If the latter occurs, you may have overestimated your maintenance needs to begin with, or your metabolic rate is still not fully restored to baseline.

If you have a goal of further weight/fat loss, than you can implement a moderate caloric deficit once again. However, you want to avoid an aggressive deficit once again, as it may lead

to a similar metabolic downregulation as occurred previously.

Layne Norton has previously said “Diet on as many calories as possible!”

What are diet breaks?

In recent years, ”cheat days” have become widely popular where individuals who have been following a calorie restricted diet will eat unrestricted for a day and can sometimes consume 3 – 5 times their maintenance needs.

The proposed rationale for cheat days, is to provide such a large amount of energy in 24-hour period, that our metabolic rate has no choice but to increase considerably. We, of course, know from quite a bit of evidence that this is no way true and cheat meals/days can do a lot more harm than good.

For example, take an individual with a maintenance of 2,400 kCals/day. They have a cheat day, consuming 6,000 kCals through various processed foods and snacks. Their metabolic rate only increases by 50-100 kCals/day but they have consumed 3,600 more kCals than they needed!

Diet breaks are a more evidence-based, and practical strategy for those who are regularly following a calorie-restricted diet. This is known as a diet break and involves an individual returning to their maintenance calories for a period for 1-2 weeks, depending on the length of their diet.

The reason for this is similar to the previous ‘Reverse Dieting’ method where you are refeeding the body so as to prevent a slight downregulation of the metabolic rate that can occur in response to continuous dieting. However, once again, this should not be considered for those that are simply following a moderate calorie deficit (5 – 10% of energy intake).