Why am I not losing weight with Couch25k? - Couch to 5K

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Why am I not losing weight with Couch25k?

pianoteacher profile image

I've seen lots of posts on here with regard to losing weight. I've tried a few times to answer those posts but always feel I haven't provided enough information for it to be really useful. So I decided to write a much longer post about the science behind weight loss and here it is!

While Couch25k is not designed as a way to lose weight many people find themselves here as part of a wider goal to lead a healthier life and shed some pounds. Lots of people post here asking why they have not lost weight and in some cases why they have gained during the programme. Hopefully this post will provide you with some of the reasons why this happens.

Firstly, in order to lose weight you must be in a calorific deficit - burning more calories than you consume. Weight loss plans such as Slimming World, WeightWatchers et al are designed to put you in a deficit by swapping high calorie “unhealthy” foods for lower calorie “healthy” choices. If you are on one of these plans and it is working for you stick with it – you are in a calorie deficit! It is however perfectly possible to overeat “healthy” foods so if your weightloss has stalled read on and hopefully you will find some answers as to why.

Lets address the basics.

What is a calorie?

A calorie (kcal) is a unit used to measure energy. More precisely it is the energy needed to raise the temperature of 1 kilogram of water through 1 °C, it's commonly used to measure the energy value of foods.

3500kcal roughly equates to 1lb of fat.

What is a calorie deficit?

A calorie deficit is burning more calories than you consume.

What is a calorie surplus?

A calorie surplus is consuming more than you burn.

What is BMR?

BMR is Basal Metabolic Rate. It is the number of calories needed to keep you alive. No activity is included in this – think coma!

What is NEAT?

NEAT is Non-Exercise Activity Thermogenesis. It is the energy expended for everything we do that is not sleeping, eating or sports-like exercise eg walking to work and at work, housework etc

What is TDEE?

TDEE is Total Daily Energy Expenditure. This is BMR+NEAT+calories burnt from exercise.

Eating the same number of calories as your TDEE will mean you maintain your current weight, less will mean you lose, more that you gain. Other things can affect scale weight but more on that later.

How to calculate your TDEE.

There are many calculators available online which use various equations to help you to work out your TDEE. The number of calories needed will vary from person to person – how tall you are, how much you weigh and how active you are all affect this number. If your weightloss has stalled you don't need an online calculator as you can work out your own TDEE by logging what you eat over the course of a week (using a site such as MyFitness Pal) adding it all up and dividing it by 7. It is important to note at this point that you do need to log as accurately as possible by weighing and measuring the food you eat. I know this puts a lot of people off but if you are determined to lose it really isn't as bad as it sounds!

Once you have established your TDEE you then need to start eating less in order to lose. I said earlier 3500kcal =1lb so cutting your intake by 500 calories a day will mean losing 1lb a week. For the majority of people this is the number to use. Note that women should not eat less than 1200kcal and men 1500kcal unless under medical supervision. While it may be tempting to accelerate the process by cutting more agressively, like Couch25k, weightloss is best approached with a slow and steady mentality.

Many people use the NEAT+exercise method and calculate their exercise burns separately via an activity monitor. These monitors often overinflate calorie burns (as do machines at the gym) so while it would be nice to think we are burning lots of calories during our runs the reality is that it is probably quite a bit lower than the technology may lead us to believe. If you're eating back exercise calories and not losing this might be something to consider.

Things which can affect scale weight

When we lose “weight” what we actually want to do is lose fat. The weight we see on the scales can vary from day to day depending on a number of factors eg when we last went to the toilet, what types of foods we have consumed. These daily fluctuation are perfectly normal but in terms of what we are discussing here they are not real weight. They are however frustrating as they can mask fat loss. Here is a bit more on one of the most common reasons for the fluctuations:

Water Weight

For those who have a menstrual cycle it is important to remember that this can cause fluctuations in scale weight - some people report as much as 7lbs!

What you eat has an impact too. Salt and carbs both cause the body to retain water but in different ways. I'm not going to go into too much detail about exactly how here but in simplified terms too much salt in the diet is bad for you whereas carbs provide the muscles with glycogen which is a positive thing.

Exercise also causes water retention. When we begin Couch25k we will be using our muscles in a new way. In very simplistic terms this means as we use them we cause tiny tears in them which fill with water. It's nothing to worry about, perfectly normal and will lead to your muscles becoming stronger over time.

Next I'd like to address one of the most common misassumptions about why your weightloss has stalled:

Muscle Weighs more than Fat

It is indeed true that muscle is more dense than fat. As you build muscle your scale weight can remain the same or even increase while your clothes size decreases. This is unlikely to be the cause of your stall in weightloss though. Here's why:

In order to build amounts of muscle significant enough to affect your scale weight you must be in a calorie surplus combined with progressive overload in strength training (what body builders term "bulking"). Females have to work especially hard as they don't have enough testosterone to help grow that muscle. Running is primarily cardio and most people would decrease the amount they do when bulking not increase it.

This does not mean that you're not getting stronger from running or that your shape won't change - it just means that this isn't the cause of the lack of scale movement.

Do remember that weightloss is not linear – meaning that even if you stick rigidly to your 500kcal deficit you won't necessarily see the scale move by exactly 1lb a week. Stick with it though because in the long term you will lose.

If you're still not losing weight after you have acted on all the information contained here please do consult a doctor. There are some medications and medical conditions which do make weightloss more difficult and require medical supervision.

You've made a huge leap forward to a healthier life by commiting to Couch25k and I wish you every success in achieving your weight loss goals.

30 Replies

Really useful post. Thank you.

pianoteacher profile image
pianoteacherGraduate in reply to Pippayoungart

Thank you x

Dexy5 profile image

Thanks Pianoteacher, I am appreciating the improved body shape, if not the weight loss I expected. But I am sure that wasn’t helped by high tea last week.😉🍰

pianoteacher profile image
pianoteacherGraduate in reply to Dexy5

Gotta love a high tea :-) Glad you're seeing improvements in body shape x

MickGJ profile image

Fascinating stuff. One of the big things I learned from this programme is how efficiently humans use energy when it comes to walking and running. Cycling--even better.

Which is great if you want to go for miles on a Mars bar, but not so much if you want to lose weight.

pianoteacher profile image
pianoteacherGraduate in reply to MickGJ

Haha! Miles on a Mars bar - I'm going to nick that :-)

Very helpful, kind , thoughtful and a good reference.

Very well done you.🌟👏👏

pianoteacher profile image
pianoteacherGraduate in reply to Tbae

Thank you.

I hoped it would be a good reference - it's just too much to cover in reply to individual posts. Happy to answer any questions people may have as well - where I can! x

Tbae profile image
Tbae in reply to pianoteacher

Your a star.👏👏

All about continuous learning.

Today I was at my medical referral group our sports leader was telling as about GTO and it’s function.🤔

Google it.👍

Importance when stretching after a run or any exercise session,this mechanism protects us if we overstretched too quickly initially, hence rendering our good intention and limiting the value and effectiveness of our effort.🙈

Something like that,but definitely worth being aware of it to get an effective post exercise stretch.

Take care and keep enjoying.🌟👏👏

pianoteacher profile image
pianoteacherGraduate in reply to Tbae

Very interesting - our bodies are so clever!

Jay66UK profile image

Thanks so much for this.

I’ve pretty much always battled with my weight (except that dream period between puberty kicking in and about 30 when I seemed able to eat anything).

I am definitely leaner than I was before C25K. I just need to control the calories in!

pianoteacher profile image
pianoteacherGraduate in reply to Jay66UK

Glad it's useful to you :-)

The health benefits of this programme are amazing and once you get the "calories in" bit under control you will see the weight shift x

Guesty26 profile image

Great post. Since starting this programme i have lost a bit of weight but combined it with a low carb diet and fasting. Basically on days where i have been running i have a bullettproof coffee and banana for breakfast then do my run and eat low carb lunches and dinners. The no run days i try to only eat low carbs between 12pm and 6pm therefore having 2 meals that day and fasting for the rest, it works for me. I don’t count calories, don’t have sugar, crisps, bread etc unless its a treat night which is once a week. Ive tried all diets and this routine seems to fit my life, horses for courses i guess. We are running now which has got to be mega beneficial too.

pianoteacher profile image
pianoteacherGraduate in reply to Guesty26

I'm glad what you're doing is working for you. There are many ways to get yourself into a calorie deficit.

I have an adult piano student who has lost a really significant amount on what sounds like a very similar way of eating to yours. I believe it is only actually necessary to count calories when what you're doing isn't working x

Guesty26 profile image
Guesty26Graduate in reply to pianoteacher

Totally agree ive done it before and will probably do again in the future.

Excellent write up . My Aim is just to maintain my weight as I have quit smoking and post that normally u gain around 10 lbs . So for C25K and not overeating(despite craving to eat sweet ) is helping me to keep my weight under check .

pianoteacher profile image
pianoteacherGraduate in reply to Grimreaper

Well Done on giving up smoking! I was a "social smoker" (aka whenever I had a drink 😂) most of my adult life but haven't touched one in about 2 years. It really is the best thing you can do for your health x

runner56 profile image

Excellent, helpful and informative.


Really informative read, thank you for taking the time to share this with us.

This is an informative and helpful post. Thank you.

Zest :-)

But since running I feel hungrier! I still have that surplus wheel around my tummy that isn’t budging. I’m on W6R1.

pianoteacher profile image
pianoteacherGraduate in reply to MeetaPatelHove

Hi Meeta it's very common to feel hungrier and we do need to fuel our workouts. It's all about balancing what we consume with what we expend. Are you tracking what you eat? In order to lose weight we need to eat less calories than we burn as explained in the post above x

Ok. I’ll start tracking and see how can reduce the calories. Thanks so much for your advice

roseabi profile image

This is really excellent, thank you for posting it, PT!!!! I will pin it xxx

pianoteacher profile image

Thanks roseabi - I think it might already be in one of the FAQ posts x

roseabi profile image
roseabiPartner in reply to pianoteacher

Ha! I didn't spot that this is an old post - that's what I get for looking at HU on my phone 😄😄😄

Precentrix profile image

lol I've actually put ON a stone, and I've not been eating more than usual. I HAVE visibly lost fat and toned, and I don't really care as long as I feel fitter. And I've been swimming once or twice a week as well as C25k, and walk quite a lot. Metabolism is a weird thing.

pianoteacher profile image
pianoteacherGraduate in reply to Precentrix

That's great that you feel fitter - scale weight should never be the primary goal. I've put on about half a stone since I began running last year. I do have a bit more visible body fat but I'm prepared to accept that as I felt I needed more energy to sustain myself for longer runs 🏃‍♀️💪🏃‍♀️

So interesting..thank you

As a little background, I've "grown" over the last ten years, and last summer was carrying a less than healthy amount of excess weight/fat. At that point I reached a critical moment and decided that I had to do sth. But what to do? "Eat less, move more" seemed the obvious choice, didn't it? Unfortunately not!

Over the last year, I've spent some (too much, my wife says) time reading books, magazine, blogs, articles, and watching videos. Now I understand that the calories in-calories out model is flawed. It fails to address the ultimate cause of weight gain. You cannot lose weight long-term by reducing your calories in and burning more calories than you consume. When we decrease what's going in, our body reacts by lowering our metabolism and hormonal changes make us hungry. We eat less, our body lowers; it's a vicious circle.

What is the ultimate cause of weight gain? Weight control is a hormonal issue: the insulin hormone, to be exact. When our insulin is high, we enter fat storage mode. What makes our insulin levels high? Typically refined carbs found in everyday foods and snacks, and also starchy foods like rice, pasta, flour, root veg.

Since last summer, I've actively been managing my insulin levels by avoiding refined carbs as much as possible, and eating enough protein and fat rich foods. Today I'm around 15kg lighter than I've been for some time, and feel great :) My running has also left me lean and toned. Win:Win.

I'd like to leave you with these two videos. The first is a presentation by Dr Jason Fung, a renowned expert in diabetes/obesity, and the second is by Dr Becky Gillaspy from the 2 Fit Docs/Dr Becky Fitness.

The calorie deception


Insulin or calories: what's behind weight loss?


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