Fasting For Fat Loss Part 2: Who Shouldn't Be Fasting & Common Mistakes

Hey Folks!

Today we’re continuing our series on fasting and fat loss. In Part 1 earlier last week we discussed the most common methods of fasting, and my experiences with each of them, if you missed Part 1 you can find it HERE.

In Part 2 today we’re covering:

  • Why you don’t need to fast to lose body fat

  • Who fasting may not be for

  • The common fasting mistakes I see people making when fasting for fat loss

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Why You Don’t Have To Fast To Lose Body Fat

If your goal is to lose body fat don’t feel like you have to fast to accomplish this, there are tons of people who lose significant amounts of body fat and get very lean without ever fasting.

For some people fasting is an effective strategy that helps them control food intake, and works for their lifestyle.

Again fasting is not for everyone, and if you want experiment give it a shot, but don’t cling to it as the only way or magic bullet, because it isn’t. If it’s not for you no need to force it.

I want to mention this because many strategies like fasting become popular, and people feel like if they’re not doing it they’re missing out.

The leanest I’ve been in the past three years was when I was eating breakfast everyday, and keeping a watchful eye on my calorie and macronutrient goals.

Whether you decide to fast or not keep in mind the biggest rocks for your fat loss are always going to be eating the right amount for your goals, proper strength strength training and managing your stress/sleep.

We also need to consider that there are people who fasting will not work for and could actually do more harm than good.

Who Fasting Might Not Be For

Adrenal Disorders/Exhaustion:

If you have any adrenal dysfunction or exhaustion, fasting isn’t a good idea and could easily make those adrenal problems much worse.

Fasting would place a larger burden on the already worn out adrenal glands to produce more stress hormones for the purpose of mobilizing stored energy while food is not available.

If you adrenals are already dysfunctional, then fasting will only exacerbate the problem.  

Sleep Deprived Individuals:

In a state of sleep deprivation the body will already have a difficult time regulating blood sugar levels leading to extreme food cravings and energy crashes.

There will be an overabundance of the stress hormone cortisol due to the blood sugar dips from lack of sleep.

Someone who is chronically sleep deprived is already in a state of chronic stress and fasting only adds to this burden.

People notice their appetite is dysregulated during periods of sleep deprivation, and they become more impulsive around food, which doesn’t go well with trying to fast.

With someone restricting food during a fasting period I could see it being much more difficult to not go overboard on food when they break the fast causing binge like behaviors.

Sleeping for 7-9 hours per night is a requirement in my book if you’re going to engage in any kind of extended fasting.

Over Exercisers/High Intensity Athletes:

If you’re trying to exercise for long periods of time or do high intensity exercise that relies heavily on glycogen for performance such as crossfit or mixed martial arts you can very easily tank your performance by fasting at the wrong times.

If you’re going to fast and engage in high intensity exercise I would do it a minimum of one day removed from high intensity work.

This means you’d have had a full day of eating after your last intense session to fuel recovery, and your fasting would be a full day away from your next session so you can adequately fuel your next session in the gym.

Those With Very Stressful Lifestyles:

If you’re already a high strung individual with a highly stressed lifestyle that involves not getting enough sleep or eating enough throughout the day, fasting is not a good idea.

By tossing fasting into the mix it will only increase the stress burden on your body without providing any additional resources to recover from the stressor.  

In turn this will increase stress hormones to an excessive levels which will leave you feeling burned out, lethargic and disrupted sleep and libido.  

Pregnant Women:

I hope this goes without saying, but for my conscience and on the outside chance that anyone who is reading this is pregnant:

You should absolutely not even be thinking about intermittent fasting while pregnant, period.

You’re growing another person inside of your body, and that requires additional energy and calories from food.

You need to eat, not just for you but for the health of your child too, you’ll be providing that human all the resources necessary for them to grow into a happy healthy baby with your eating habits, restricting calories and fasting is not conducive to this at all.

Those With A Tendency To Binge:

When someone brings up fasting and not losing body fat, I always ask what it looks like when they break their fast and eat.

There is are two common themes in these scenarios:  

1.) Not being able to control their appetite when they break the fast and eat.

2.) The first leads into this point which is far exceeding what they need to eat to lose body fat.

Many times people will fast the entire day and then eat one to two larger meals around dinner time.

Without a plan to follow these meals don’t have a structure to them, and people wind up eating everything in sight.  

By fasting all day it can create a hunger bottleneck that bursts when you break the fast  and causes uncontrolled eating.

I would have these same urges when I would fast and paired it with low carb and then tried to perform intensely in the gym. I now recognize how dumb this was and actually hurt my performance in the gym and body composition goals.

Live and learn folks, but try to learn from mistakes!

If you have a tendency to restrict and binge with food, then intermittent fasting could do more damage than good.

Fasting Fat Loss Mistakes:

Not Controlling For Calories

Fasting can be an effective way to control eating habits, and allow you to eat naturally in a manner that creates a calorie deficit for fat loss without overthinking it.

The fact remains though, to lose body fat you’ll need to be in a calorie deficit by eating less than you expend, or having a higher work output that allows you burn more than you’re consuming on a daily basis.

If you find yourself fasting and you’re not losing body fat you may need to track with a food journal or my fitness pal for a few days to see where you calorie intake is compared to what you’d need to lose body fat.

Not Eating Enough

This may seem like an odd point to have right after discussing that you may be overeating, but if you’re chronically under eating and fasting at the same time you’re  more likely to cause adaptations that make you burn fewer calories throughout the day.

When someone is in an extreme calorie deficit for a long period of time, the body slowly down regulates different components of the metabolism to be more efficient and expend fewer calories at rest and while exercising.

Whether you realize it or not you’ll move less… and in turn expend fewer calories.

Your daily movement like walking, fidgeting or making food and washing the dishes will burn fewer calories through a reduction in what’s know as non exercise activity thermogenesis (NEAT).

You may burn fewer calories when engaging in that non exercise movement as well. No your body doesn’t hate you it just adapts and that’s what’s helped us survive this long.

Along with the reduction in calorie expenditure through NEAT, your body will make you burn fewer calories during exercise which is the the thermic effect of exercise (TEE).

Your sessions in the gym or cardio sessions will feel tougher to get through, and your body will become more efficient by making you expend fewer calories during a times in the gym.  

Not to mention the calories needed to digest and break down food called the thermic effect of food (TEF) will be lower because you’re eating less than you have before.

You’re Losing Fat, But Retaining Water

When someone has been in a calorie deficit for a long period of time without a break from dieting and adds in other stressors such as fasting or over exercising the body will up regulate stress hormones in an attempt to mobilize available energy in the body.

These stress hormones also cause you to retain a significant amount of water and can stall weight loss, but not fat loss.

The amount of water someone retains can offset any potential fat loss they would otherwise see when they step on a scale.

This is the reason why people have planned higher carb days. These higher carb days help to fuel recovery, keeps hormones healthy and blunts stress hormones and negative adaptations of aggressive dieting.

Many times people wake up the day after these high carb days a few pounds lighter and looking leaner in the mirror due to the water loss from blunting stress hormones with increased carbs.

Keep in mind though these higher carbs days are planned and there is structure to them much different from a cheat day.

Fasting Every Day

I think fasting can be a good practice however some people will not be able to handle the stress burden of fasting every single day.

Some folks can fast everyday and not be phased by it, however people like myself and others I’ve spoken to will see repercussions when fasting too frequently.   

In my personal experience, when I fasted everyday and was low carb I felt great in the beginning, but that eventually wore off.

Eventually I started to feel worse and worse and would hit a brick wall during the day that required massive doses of caffeine to keep me upright, and in complete honesty I still drink a good amount of caffeine daily.

However in these days with low carb and fasting too frequently my energy, workouts, and sleep all went to shit quickly.  

I stopped fasting everyday and started reintroducing more dense carbs daily and my energy, workouts and sleep all improved.

Now when I fast I do it once or twice a week if at all, and many times it’s by accident.

If you want to use fasting as a strategy to help you control your food intake for fat loss doing it everyday may not be the best strategy as it can come with some down sides.

As you can see these are some very common mistakes that people make when it comes to fasting and fat loss, but they are all very easy fixes you can change today if you’d like.

Stay tuned for Part 3 of this series where we’re discussing the solutions to the above fasting issues, and how to organize your own fasting protocol

Fasting For Fat Loss Part 1: Popular Fasting Methods

Before we can get started I need to cover the necessary bases with a quick disclaimer:

Because I know that people like to get extreme with these kinds of things I want to clearly state:

The information in this blog is not medical advice. This is not meant as a replacement for any medical care or advice. Please consult with your physician before you decide to make any changes to your nutrition or exercise routine. If you choose to take action on the information in this newsletter without the consent of your physician you are accepting the full responsibility for your actions. By using the nutrition information from this blog you recognize that despite all the precautions on the part of Alex McMahon and Evolve Nutritional Therapy LLC there are risks of injury or illness that can occur because of your use of this information and hereby waive, relinquish and release any claim that you may have against Alex McMahon and Evolve Nutritional Therapy LLC as a result of future injury or illness associated with the misuse of the information contained in this blog.

Back to our regularly scheduled blog now...

An in depth conversation with my friend Frank who just did a four day water fast fast a few weeks ago was part of the inspiration for this. 

Intermittent fasting for fat loss is a subject thats come up a lot recently with people, and the interest seems to be at an all time high so I wanted to address the subject and how it relates to your fat loss goals, and explain some common mistakes and myths on the subject.

In fact I have a client who’s fasting every day from sun up to sundown following Ramadan this month from May 26th through June 24th and we’ve arranged her nutrition according to this practice to help her better manage her energy and appetite during this phase.   

Before we get too far I wanted to explain the different variations of fasting that people commonly use, and give my experience with the ones that I’ve used.

 I actually used the Eat Stop Eat  fasting (24 hour fast) once a week for 8 weeks to drop body fat and fuel my training for two powerlifting meets this past April.

I'll  get into that a little later, but lets take a look at the most popular methods people use when fasting.  

Most Popular Methods Of Fasting

There’s some debate over what constitutes breaking the fast. Many experts say that anything other than water including black coffee breaks the fast.

Jeff Rothschild an expert in the area explains that coffee even if it does break the “fasted” state can be beneficial because it helps to set the biological clock in our bodies, and kickstarts a number of different organ functions and enzyme production.

From a technical standpoint and to keep things simple any calorie free beverage, and even a splash of cream in your coffee while technically breaking the fast is not the end of the world, or something to worry too much about.

Skip Breakfast

This method of fasting is what many people will find to be the easiest to follow. You simply just skip breakfast and then have lunch as your first meal of the day and stop eating after dinner.                  

This is very similar to the Leangains protocol but doesn’t require counting the fasted and fed hours or higher and lower calorie and carb days. It allows for greater flexibility.

I believe that skipping breakfast is a great place for people to start with fasting, and makes for an easy transition to the 16/8 Leangains method.

I like the Leangains method because it provides more structure to the fed and fasted times, and can work very well when adhered to.  

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16/8 Leangains

This style of fasting was popularized and brought to the mainstream by Martin Berkhan. It’s one of the most popular protocols in the health and fitness world.                 

With Leangains you use a 16/8 fasting and feeding schedule. You’ll fast for 16 hours each day, and then consume all your food in an 8 hour window.                        

With this style of fasting you would stop eating after dinner around 7-8pm. When you wake up in the following morning, instead of eating breakfast, you would have coffee, tea or water and wait until lunch time at 11am-12pm to have your first meal.

I find the 16/8 fasting and feeding structure has a natural flow to it that’s done easily, and isn’t disruptive to everyday life.  This used to be the style of fasting that I used the most in the past, but recently started playing around with another method I talk more about below.               

Eat Stop Eat (24 Hour Fasts) 

This protocol of fasting was popularized by Brad Pilon. His approach is very simple; you do one to two twenty four hour long fasts per week; and eat normally the other five to six days of the week.

You eat normally on non fasting days, and during fasting days you go a full twenty four  hours without any calories  just drinking water, coffee, tea or any other calorie free beverage.

The way that the ESE style fast is structured it still allows you to eat every day, even though you are fasting for a 24 hour period.

For example if you wanted to fast on Wednesday, you could eat breakfast at 8am, then not eat again until breakfast at 8am on Thursday still eating each day.

My Recent Experiment With 24 Hour Fasts

As I trained for my powerlifting meets this last April my training was far more intense than it had ever been before.

As a result of training sessions that took upwards of two and a half hours sometimes I was ravenous, and needed to eat more to perform in the gym and recover.

My main concern during this period was performance, not fat loss or body composition. 

As I got stronger I also gained weight which was entirely expected, however I still needed to drop around ten pounds to make the 74kg (163.1 lbs) weight class.

I had to find a way to eat enough to fuel performance on a daily basis, yet create a calorie deficit to drop body fat for the powerlifting competitions.  

I tried cycling calories and macros on training and non training days but it was more effort than I felt like was necessary, and was more difficult for me to stick to.

After having the pleasure of getting on skype with a researcher and all around great guy who I greatly respect named Alex Ritson I told him I'd rather fast for 24 hours than diet a little each day. 

As a result Alex helped me figure what my intake should be on the non fasting days to make weight for the 74kg weight class.

I would consume zero calories on Mondays, and then eat 2,400 calories the other six days out of the week so I had the necessary fuel for recovery and performance in the gym. 

I’m a bit of an extreme person in this regard, and would rather fast for a full day than have to diet a few days out of the week so this approach actually worked really well for me. 

I know this is a little extreme to some, but there's some insight into my mindset/personality type for any of you wondering.

Using this approach I actually came in  lighter than projected and weighed in at both meets right around 158 pounds.

Fasting isn’t the right approach for everyone, and there is nothing magical about it however it can help some folks.

I also wouldn’t recommend trying to start off fasting with a twenty four hour fast either, start smaller and work your way up if you’re curious.

Next week we're going to cover why you don't have to fast to lose body fat, and who fasting might do more harm than good for. Thanks for reading!


Do You Have A Slow Metabolism ? (Part 1 &2: Underestimating Food Intake)

We’ve all heard someone mention how they gain weight much quicker than others, and have a more difficult time losing fat as well.

From the outside looking in it may appear that this person has been cursed with a slow metabolism, but for many people this isn’t actually the case.

If you feel cursed with a “slow metabolism” this blog might bring to light that you’re not cursed, and have been making some small mistakes that you can avoid from here on out.

I would also like to add the caveat that there are people who have diagnosed medical conditions, and take medications that can make fat loss more difficult.  

When someone doesn’t know they’re consistently eating more calories and larger portions than they need it’s very easy for people to underestimate their food intake on a daily basis.

Seemingly small daily mistakes can add up over the weeks, months and years and only make you more frustrated and looking for reasons why fat loss is happening when you think it should be.

Before we can discuss fat loss and the metabolism it’s important to discuss a hot topic for some people... calories.

Whether you want to count them or not just know that they count when it comes to fat loss, and you have to be in a calorie deficit to lose body fat.

But we don’t just eat calories, we eat food and there are lot of different things that impact and drive our dietary habits beyond calorie content that we’ll discuss later.

Why calories count for your fat loss

The diet someone chooses to use for fat loss can differ from person to person based on their personal preference.

Paleo, vegan, high carb, low carb, flexible dieting or ketogenic diets can all work.

There are a multitude of of different diets that people use to achieve fat loss, and what matters most is finding something you can stick with, and doesn’t feel overly restrictive.  

No one single diet is magic when it comes to fat loss, and they all adhere to one specific principle to help elicit fat loss which is creating a calorie deficit.

This means that you expend more calories than you take in through food on a regular basis.

As an example low carb and low fat both eliminate an entire category of macronutrients which makes it easier to eat fewer calories.

Vegan and paleo limit food choices and focus on high satiety natural foods, which keeps you fuller for longer and creates a calorie deficit without counting or tracking.  

A calorie deficit can be created by changing food choices on a diet, tracking calories or macros or using basic portion awareness.

You can also move more throughout the day and expend far more calories that most people would think logical, I wrote a blog on the topic HERE.  

The difference in effort it takes to remove 300 calories from your food compared to trying to burn off an additional 300 from movement definitely favors just trying to eat a little less.

People like to argue whether fat loss is all about calories or quality of food, but it’s really both of them.

You can eat too much of a healthy food and exceed your calorie needs very easily. Take nuts and nut butters for example, they’re a healthy and tasty food, but also contain a lot  of calories for 1 tbsp, and are very easy to overeat.

Regardless of what people say you can still over consume calories from a healthy food and entirely stall out fat loss and even gain body fat.

By consuming mostly whole foods like protein, vegetables, fruits, starches and healthy fats you’ll  stay fuller for longer and it’s an easy way to create a calorie deficit.

The point here is that no matter where your calories from they count, and you’ll need to create a calorie deficit for fat loss to happen.


1.) People regularly leave out food they're eating:

This isn’t an attempt to be deceitful by any means, but most people really aren’t aware of the amount calories their food contains, or literally forgets some of the food they've eaten throughout the day. 

There’s study after study that show people unintentionally under report the amount of food they’ve eaten for the day when asked to recall their intake  or do a food journal.

Sometimes those participants underestimate their calorie intake by upwards of 40%, however even dieticians still miss the mark by 223 calories per day as well.  

If you think you’re eating 2,000 calories but you’re really eating 40% more than that it would be 2,800 calories a day.

That’s an extra 5,600 calories over the course of the week or 1.6 pounds of theoretical fat, while we know that not all that would go into fat stores, it goes to show small mistakes can add up to large frustration due to misreporting.  

That 500 calorie deficit per day you set to lose one pound per week at 2,000 calories  is completely gone, and your weight may even start creeping up.

All those little snacks you ate that you forgot about, or the food samples at the grocery store and the bites you ate while making dinner all add up in the long term, especially if your fat loss has stalled out for a long period of time.  

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2.) Portion sizes:

Most people were raised with the clean your plate mentality, and when that applies to eating your salad or brussel sprouts it’s not a problem.

When the clean your plate mentality comes to more calorie dense foods that are easy to overeat these larger portions make you normalize a greater consumption of food, nut for hunger reasons but because of habit.  

It doesn’t help that most of the foods we buy in packages at the store, and portions at restaurants have increased in size over the years.

This only normalizes the behavior of overeating even more.  

If you’re using bigger glasses, larger bowls and plates and this influences the amount of food you eat on a daily basis too.

An identical portion of food on a smaller and larger plate looks smaller on a large plate,  and larger on a smaller plate.

Brian Wansink the author of Mindless Eating and Slim By Design showed repeatedly that if people are served more food they will eat more food without noticing or feeling more satisfied than they would with a smaller portion.

3.) Mindless Eating:

As a society we’re more distracted than we’ve ever been with have unlimited access to information,videos and social media platforms that we derive joy from.

We’re flat out addicted to our devices, and this isn’t to point a finger but I’m just trying to raise awareness of how this can impact your eating habits.

These distractions will lead you to eat in a much quicker fashion without pausing or putting the fork down.

You can eat an entire meal in less time than it takes your stomach and brain to communicate and send the signal that you're full (roughly 20 minutes)

when was the last time you took a full twenty minutes to eat a meal and truly ask yourself am I really hungry for the next bite ?

When you eat too quickly it becomes very easy to eat more than you need, and consume excess calories.

When people eat in front of a T.V. they no longer base their meal duration on hunger, but on the length of a show to know when they’re done eating.

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4.) Even food labels can be wrong:

If the majority of your foods are coming from packages that have food labels you could be eating more than you think in terms of calories.

The FDA is responsible for the labeling of calories on a food package, however the actual calculation of the calories/macronutrients of a food is up to the food manufacturer.

For this very reason the law allows food labels to be incorrect by upwards of 20% for the actual versus claimed calorie or macronutrients on a food with a label…

As an example a 100 calorie snack pack may really contain 120 calories, and while this may not seem big if that person has 3 of those 100 calorie snack packs per day that’s 60 calories a day and an extra 420  calories a week, and that’s just from a small snack pack.

5.) The Hyper Palatability of foods

When we discuss hyper palatable foods I’m referring to foods that hit on the reward center in your brain as a way to encourage you to eat more of that food.

This mechanism used to be critical for our survival as a way to help us gorge on calorie dense fatty and sweet foods when they were available to store body fat in case of a famine.

The problem is these days we have hyper palatable sweet and fatty food available every waking minute of every day.

Now that these sweet and fatty calorie dense foods are around every minute of every day it leaves us at odds with our biological drives to eat for survival, and the struggle to not get obese.

These hyper palatable foods can also increase your mood for a short period of time due to stimulation of the reward center in the brain,

However when your mood returns to normal, and if you end up in a worse mood and want to feel better you’ve now created the connection between mood and food.

This is when you’re main motivation for food consumption is no longer physical hunger, but to achieve a certain feeling or alleviation of a negative mood state.

Maybe you set out to just have a bite of that cookie, ok ok I’m just going to have one cookie. Then that one cookie turned into a full sleeve.

You just set out to have few handfuls of buttered popcorn but then 15 minutes later you’ve eaten the whole bag…..

This food for your could be something totally different seemingly healthy like almond or peanut butter.

Honestly I can easily over do it with peanut butter! and have in the past before I realized this and decided to only get it at certain times and not at others.

Whether we want to admit it or not there’s specific foods that stimulate the reward pathway in our brain, and encourage us to overeat.

These foods will be different for folks. For me it might be peanut butter but for someone else it might be corn chips, ice cream, pizza or bread/pasta.

This leads perfectly into another large point that most people neglect when it comes to calorie awareness which is your food environment.

6.) Food Environment factors:

We make over 200 food related decision every single day, many of which we’re entirely unconscious of many of. This is why mindless eating is important to pay attention to.

How can you can you easily alter and change your mindless eating habits ?

By changing your food environment.

Let’s say you come home after an especially stressful and long day at work. You’re hungry, tired, stressed and don’t want to make any more decisions.

Right there on the countertop in your kitchen there’s a basket with cookies and potato chips. At this point the likelihood of you dipping into that basket is especially high.

However, what if you came home and instead of the cookies and potato chip basket there was a bowl of fruit with apples, bananas and oranges on that countertop.

Well then your options would be to have a couple pieces of fruit that would tide you over until dinner and keep you much fuller for a fraction of the calories, be higher in fiber and satisfy that sweet tooth of yours.

This is a perfect example of how your food environment can shape your choices without any thought.

Here’s a few ways to positively alter your food environment:

1.) Keep fruits and veggies in plain sight: Put fruits and vegetable in a basket on the countertop where you’re likely to walk by. Have a vegetable tray or chopped up veggies and fruit in the front of the fridge, or freezer where you’ll see them. Get lots of different colored fruits and veggies to make them enticing. No one ever wrecked their health eating too many colorful vegetables!

2.) Keep Easy High Protein Foods In Your Fridge: Make sure your fridge is stocked with easy to grab high protein options like cottage cheese, greek yogurt, deli meat or leftover cooked meat. Toss in some pre cut vegetables like carrots, jicama and sugar snap peas for some color texture and fiber!

3.) Make The Kitchen Less “Lounge Friendly”: when it comes to the actual arrangement of your kitchen making it a less lounge friendly area will help you to spend less time in there mindlessly munching when you’re not actually hungry.

To reduce the lounge-ability of your kitchen remove furniture, take chairs away from kitchen island, ipads and place the TV’s, small desks, computer or Ipads elsewhere.

4.) Half Plate Rule: At each meal and especially at social events, making sure that at least half your plate is filled with vegetables or fruit. This will ensure you’re staying full, getting enough plants in and still able to enjoy social outings while staying on track.

5.) Assess Work And Other Food Environments: Position the sweets jar or designated doughnut area as far away as possible at work. Put sweets in a jar that isn’t see through and don’t hover by the snacks you’re trying not to eat. Drive home a different way to avoid fast food restaurants or take a walk during lunch to prevent overeating or unnecessary snacking on junk food. Find ways to make your food environment work for you, not against you.

In Part 3 of this series we're going to look at some of the metabolism adaptations that take place when someone constantly yo yo diets, or is an aggressive calorie deficit for too long without a diet break. 


Do You Have A Slow Metabolism ? (Part 3: Metabolism Adaptations)

In the past two parts of this blog series we took a look at the many ways in which people unintentionally underreport their food intake, and misrepresent how much they're eating by accident. 

A large part of this comes down to the calories coming in being underestimated or unaccounted for due to poor calorie and portion awareness. 

But what about when someone is being accurate with their intake and still not losing weight ?

This leads to frustration, and some can quickly lose faith in the process thinking it isn't working for them. 

This is when a coach can be invaluable to give objective explanations of why weight loss stalls and plateaus as a normal part of the process, and doesn't mean fat loss isn't happening. 

When you thinks that you should be losing weight, but aren’t and even worse; possibly gaining a little weight it can cause knee jerk reactions that aren’t helpful for your long term goals.

However these are normal hormonal, water and metabolic adaptations that take place during dieting. 

In today’s blog we’re looking at the ways in which your body adapts to you losing weight, aggressive dieting and prolonged periods of stress.

These adaptations and excessive stress impact your calorie expenditure, and weight loss trends.

Something else to keep in mind is that these adaptations are a result of getting leaner which is why someone doesn’t eat the same amount and continue in a straight line to their ideal body composition.

Adjustments to calories, macros and even some activity will need to be made based on your rate of progress to keep fat loss happening. 

Your Energy Needs Change The Longer You Diet

There are a few different reasons that your calorie needs change as you diet, and they all pertain to different components of your metabolism and how it’s adapting to you eating less, weighing less and the excess stress that can come along with the process of dieting and exercising on lowered calories.

Your energy needs aren’t static either and can change from day to day based on a number of different factors, this is another reason why day to day fluctuations matter less than weekly trends. 

Even if you’re eating the exact same amount each day which is difficult because you’re not a robot, you’ll be expending a different amount each day.

Basal Metabolic Rate Decreases

The energy required to support your body weight and maintain physiological function which is your basal metabolic rate (BMR) which decreases as you diet and lose weight.

In essence your Basal Metabolic Rate (BMR) decreases because a lighter body requires fewer calories to maintain than a heavier body.

If you weigh 190 pounds you may require 2,900 calories to maintain that body weight. If you diet and lose body fat and get down to 160 lbs you may only need 2,500 calories to maintain your new body weight.

The drop in calories required to maintain a lighter body weight are not entirely from the drop in BMR, in fact the reduction in basal metabolic rate is relatively small compared to other metabolic adaptations that take place. 

(The above aren’t real numbers I just made them up to use as an example, and show the idea expenditure decreasing with bodyweight.)

Eat Less & Thermic Effect Of Food Decreases

Your body has to use a certain amount of calories every time you eat to digest, break down and absorb nutrients from food, and this is known as the Thermic Effect Of Food (TEF).

Each of the macronutrients protein, fats and carbs require a different amount of calories for their breakdown. While not technically a macronutrient fiber is also very high up on the TEF rating as well.

When you’re dieting and eating less your body will be expending fewer calories to break down and absorb nutrients from the food you’re eating. 

Thermic Effect of Activity Decreases Because BMR Dropped

Because your body weight is lighter you BMR decreases and you burn fewer calories at rest, but this also applies to the calories you burn during exercise as well.

The calories that you burn off during formal exercise is known as the Thermic Effect of Exercise (TEE).

Because your body is smaller the energy expenditure needed to lift weights, run or do yoga is less, a smaller body burns less calories.

Moving Less Isn’t NEAT

Non Exercise Activity Thermogenesis also known as NEAT is all the movement you do outside of formal exercise (TEE). This NEAT includes walking, cooking breakfast and doing the dishes, fidgeting and scratching your nose.

As someone diets down and starts to lose body fat they may see a drop in NEAT levels. There is a lot of individual variation in how people’s NEAT levels respond to dieting. Most people see their NEAT decrease via less walking and moving around during a dieting phase

This is why you shouldn’t use your activity tracker to try to estimate the calories you burn, but instead as a way to make sure you’re getting a baseline of low level activity each day.

Putting the Pieces Together

When someone diets for a long period of time they will see inevitable drops in their overall metabolic rate because each part of the metabolism compensates to become more efficient in response to dieting.

BMR +  TEF + TEE + NEAT = Total Daily calorie burn or metabolic rate

As you can see just about every aspect of your metabolism adapts when someone yo yo diets or does a long term aggressive diet.  

But these adaptations go beyond the metabolism. There’s significant hormonal shifts that take place during dieting that can impact how your body responds to dieting.

Those hormonal shifts in response to dieting is what we're covering in parts four and five of this series so stay tuned!