Why low calorie diets are wrecking the nation's health and waistlines
Updated: Jan 3
Grab a cup of herbal tea and get comfy for this one...it's a little of a longer read but will be totally worth it :)
Hands up if you head straight to calorie restriction when it comes to losing weight?
Literally millions of hands would fly up at this point, and mine included back in my 20s.
In this post I want to help you understand truly why low calorie diets are wrecking the nation's health and waistlines, and why you'll want to boycott this approach, for good.
"But low calorie diets DO work"
....Well, yes, it’s possible to lose weight on 800-1200 calories per day (depending on which diet you’ve chosen). But I don’t know any woman who has done this, kept the weight off, and/or has a strong and lean physique, healthy hormones, and optimal energy levels and strength, healthy hair, skin and nails, good sleep, good digestion, balanced mood, and a healthy relationship with food and eating.
The women I work with have mostly come from a background of restrictive diets and their weight has yo yo’d over the years. These are the women who struggle the most to lose the weight they’ve gained back from all the restrictive eating and are the most frustrated, after years of struggling.
There is a massive flaw with the typical dieting advice to restrict calories as low as 800-1200 per (approx 50% deficit), it’s a flaw that quite simply keeps a person stuck in the dieting cycle for years if not forever whilst they lose weight then regain in again, over and over and over. So a clever flaw for the billion pound dieting industry some might say.
Let me now explain the flaw in this typical weight loss method, it starts with your BMR.
BMR stands for basal metabolic rate (also known as ‘resting’ metabolic rate), but to better understand the BMR and I’ll first explain your metabolism to you.
Your metabolism is the biological processes occurring in your body each day to allow you to maintain life by getting energy from the food you eat. Your metabolic rate is the speed, or frequency, of your metabolism.
Basal metabolic rate ( BMR ) is how much food (energy income) an organism will require to keep its functions active, it’s the lesser spent energy per time (at rest).
The amount of energy you need to take in each day is depends on:
Your BMR – the absolute minimum number of calories/amount of energy your body needs each day to maintain basic functions of your organs, at rest (based on your height, age, and weight).
Your activity levels - Both physical and mental, so the amount of mental energy you’ll expend across the day both mentally and physically. Physical activity includes everything from making your bed in the morning, showering and getting dressed, to jogging and going to the gym.
Your own unique set of daily life circumstances
Thermoregulation is a process that allows your body to stay inside of its optimum temperature range, and so maintain homeostasis (physiological balance)
The thermic effect of food – this is the amount of energy your body uses/spends when digesting your food. it takes energy to break food down to its basic elements in order to be used by the body.
Your BMR accounts for about 60% of your total daily energy/calorie expenditure - so there is another 40% of energy/calories that need to be taken into account, and this number of calories is dependant on your own unique set of circumstances such as your daily activity level, health status, goals and needs.
How many calories should you eat per day?
So, you’ve got your BMR which is the amount of energy (calories) your organs burn/use at COMPLETE rest each day (your brain, gut, kidneys, liver, muscle, heart, skin), and then you need to account for the amount of energy you’ll use each day performing your daily activities - this is obviously going to vary from person to person, this also includes the energy we need to think, to make decisions, to create, produce, write, invent, calculate - to be productive at work etc!
What's problem with low calorie diets?
A typical diet ‘guru’ and low calorie diets tell us to eat LESS than our BMR, everyday for a certain period of time (or forever if they had their way), which is INSANE! They are simply taking the average BMR and then slashing it in half as a way of losing weight - but it just doesn’t work like that.
What you really want to be doing is having a rough idea of how many calories/energy YOUR body needs per day - taking into account your BMR and then your daily activity level and own unique circumstances, and then take a SMALL deficit (10% to maximum 15%) off of this number to find the approximate number of calories you should look to consume daily for fat loss.
The key word here is FAT loss versus WEIGHT loss. On such a low calorie diet as 800-1200 calories per day your body will shed mostly muscle tissue rather than actual body fat. Yes some fat tissue will go, but essentially your body is looking for the energy that it’s not getting from your food, and it looks to your muscle tissue where it can break it down and make glucose. So yes, you lose ‘weight’, but it’s at the expense of your muscle mass and precious organs, which can start to shrink when they don’t get the energy they need.
What you really want is to lose ONLY body fat, and NO muscle tissue - this is absolutely SO important. Your muscle mass is so important for good health and longevity, and it’s also what gives you a lean physique and not to mention a healthy and thriving metabolism where you’re burning fat and then maintaining your ideal size once you’ve lost the excess fat.
Low calorie diets simply provide a quick & temporary fix where any results you do get are; 1) not the right results you were looking for i.e. not true body fat loss and 2) impossible to maintain because your metabolism soon starts to fight back and your body is now a fat storing machine...oh and 3) you lose a tonne of energy, and have low self worth, hormonal, mood, and digestive disturbances.
When you start to lose muscle mass and compromise your organs your metabolism (aka metabolic rate) starts to significantly slow down.
Then any ‘weight’ loss you were experiencing starts to grind to a halt (aka hitting a weight loss plateau) - and so what do you do when that happens? Likely start to restrict your calories EVEN MORE and exercise EVEN MORE, OR you just start eating normally (pre-diet) again - either way the weight piles back on again and usually with even more body fat than you started with.
On top of all this, low calorie diets have a negative impact on some really key areas of your health and you really do want to be considering all of this, no matter how desperate you are for quick results - not only are those quick results not genuine AND not going to last, but they’re also hugely detrimental to your longer term health.
Fertility and female hormonal health is massively affected by low calorie dieting. As I already mentioned above, when your body is in a major calorie deficit (even 1400 is too low) your body is now breaking down muscle mass and organs to provide itself with the energy it isn’t getting from food, add to this a tonne of exercise (especially cardio) and in this state it’s never going to prioritise sending energy to your reproductive system - and thus hormonal issues and infertility ensue. The same can be said for your immune system, your muscles, and your brain - these organs need a lot of energy each day and if one needs it more than another then the other/s are going to be pretty much inactive/unable to function at their best.
Low calorie diets often mean you’re going to be missing out on a significant amount of important nutrients and diversity of foods each day. For example all the different colours and types of vegetables provide different key nutrients and antioxidants that your body needs to function properly. We need exposure to plenty of different good fats each day, minerals, protein, quality carbs, quality and diverse range of fibre sources, etc etc. What you end up with on a low calorie diet is a low amount of everything and nothing of some super important elements of what makes up a healthy balanced diet. Cereals and bars do not provide you with quality fibre and carbohydrates, and a diet low in quality fibre and carbohydrate will soon leave you constipated and depleted of healthy gut bacteria, and constipation and compromised gut health can further slow your metabolism and reduces your thyroid function!!
How might you know if you’re not eating enough?
Some common clues are:
Ever-growing belly fat despite your best efforts with diet and exercise
Low energy and or feeling drained after exercise / poor recovery from your workouts through the week, plus aching muscles and joints.
Cravings, sometimes intense, and more common around 3pm
The 3pm energy slump
Hungry and or never satisfied after your meals
Always obsessing over / thinking about food
Binging on your favourite sugar, high carb, high salt and processed fatty (the unhealthy kind) foods
Irregular menstrual cycle and even loss of it altogether
Loss of sex drive
Feeling cold too easily and struggle to get warm
Weak brittle nails
Weak or thinning hair
Skin issues such as dry, dull, breakouts
An unhealthy relationship with food and eating
Feeling weak and or dizzy
So what can you do now if this resonates with you?
I would start by increasing your food intake slowly over a period of time. No rush with this, the important thing is that you are comfortable with each small increase and that you can work yourself up to the optimal daily food intake for you without feeling stressed or anxious about it, it needs to feel natural, so the slower you do this the better.
You could do it increments of 50 to 100 calories at a time, per day for a week at a time, and then increase by another 50 to 100 calories and so on.
The likelihood is you need to increase your daily calories (even with a fat loss goal) by a significant amount to what you’re used to, so do it in your own time.
The more gradually you do it the more comfortable and confident you will be with the notion that you actually can (and need to) eat MORE food and you won’t gain weight, in actual fact you’ll see better results, and results that LAST.
The key though is in where you get these extra calories from. You don’t want to get them from refined carbs and processed foods for example. Look to increasing some healthy fats, increasing protein, and quality carbohydrates for example after your workouts provide your body with 30-50g of carbs in the form of bananas, oats, rice, potatoes.
At the same time take a look at the amount of and type of exercise you’re doing throughout the week. Is it exercise that’s placing stress on your body and causing imbalances in your stress hormones? Or is it a nice mix of restorative stuff such as nature walks, gentle yoga, and rest days, with muscle building exercises such as strength-training/lifting weights?
Health issues associated with under-eating
When a person is consistently under-eating / dieting, especially if that’s coupled with over-exercising, some body systems can get thrown out of balance.
Some common ones are:
Digestive symptoms such as bloating and other IBS symptoms
An underactive thyroid
Compromised adrenal gland function which can lead to sex hormone imbalance
Increasing your daily food (energy) intake, and addressing your weekly exercise regime if applicable, can have a lovely healing effect on these systems. And of course the increase in foods should come from nutrient-dense foods and some superstars are:
Healthy fats from avocados, olive oil, almonds, brazil nuts (contain selenium which is great for thyroid support), walnuts, flaxseed, pumpkin and sunflower seeds, hemp seeds, olives, coconut products
‘Oily’ fish such as wild salmon, sardines, mackerel, trout, herring, anchovies
Eggs (the yolk too!), for the choline they provide and for cholesterol to help with the production of your sex hormones
Fermented foods such as raw unpasteurised sauerkraut, kimchi and kefir
Quality dark chocolate (minimum 70%) instead of regular milk chocolate, for it’s magnesium!
Liver! Because it’s so nutrient dense providing great amounts of B12, vitamin A (the active form that plants can’t provide), iron, B6, biotin, and folate.
Dark green leafy veggies (spinach, chard, kale, broccoli, cauliflower, cabbage) and also sea vegetables and seaweed.
Dive Deeper with Functional Health Testing
If you start to action the above suggestions and feel you could still do more work to optimise your health and address some niggling symptoms of imbalances still at play then functional testing could be a good next step. It’s important that testing is done under the care of a nutritional therapist (e.g. me) or functional medicine doctor so that your results are interpreted properly and suitable and safe recommendations are made for your unique case. I use functional testing with many of my clients and once we have results to work with I can put together an effective and targeted personalised supplement plan.
Some common tests I use with my clients are:
DUTCH Complete Hormones test including sex and stress hormones
A comprehensive digestive stool analysis to look at and address any gut imbalances including parasites, pathogenic bacteria and SIBO.
Total Thyroid Screen including T3, RT3 and thyroid antibodies (to check for thyroid autoimmunity)
If you'd like my help I'm here for you. Apply for a free exploratory call here and let's chat things through :-)