Starvation mode: is it really a thing?

Amy Wood - Nutritionist | 04 Feb, 2022

It's been several months since you started your weight loss journey. You've been doing everything right: accurately logging all your food and drink, staying within your calorie target, and exercising regularly. And all your efforts have paid off, as the number on the scales has continued to drop week on week – result!

...then suddenly, everything grinds to a halt! Your progress stops, and the scales seem stuck on one number despite continuing all your healthy habits. A quick internet search tells you your body has entered 'starvation mode' and your metabolism is broken. Sounds really worrying and a bit depressing...

But before you think about throwing in the towel, let's delve a little deeper – is 'starvation mode' really a thing?

Actual starvation

If the body is deprived of food for a period of time, a series of clever protective mechanisms kick in to conserve energy and keep it functioning. By 'deprived' we mean someone is eating less than half the calories they need to maintain their weight. And by 'period of time', we mean several months at least. Essential muscle and organ tissue begin to break down to provide an emergency energy source for the brain, and body functions such as fertility, temperature regulation and hair/nail growth may eventually shut down in an attempt to further preserve energy supply. These are the kinds of effects we observe in chronic cases of genuine famine and poverty.

If you've been following a sensible calorie deficit as calculated for you in the Nutracheck app, and your weight loss progress seems to have slowed or stopped, your body won't be truly 'starving'. The term 'starvation mode' is a much more dramatic term than what is really going on!

Weight loss plateaus

It is a fact that weight loss plateaus happen, so if 'starvation mode' isn’t the cause, what is really happening? It could be due to one or more of the following changes.



Smaller bodies need fewer calories

When you reduce your calorie intake by a safe, sustainable amount, you should begin to see weight loss. As your body becomes lighter, it will require less energy to fuel all the essential processes that keep you alive (your basal metabolic rate, or BMR) – a smaller body burns fewer calories throughout the day than a larger body. This means your calorie needs will decrease as your body weight decreases. To continue losing, you may need to reduce your calorie intake further. This is why we recommend updating your profile weight after every 7-10lbs or so of weight loss/gain. To do this, follow these steps.

Important! Sometimes members question the starting calorie allowance Nutracheck sets them, and think it's too high – but it is for precisely this reason we recommend people follow the target set. It will be calculated to be low enough to result in weight loss – but if you decide to override it and go lower, it can be problematic down the line if you need to reduce your calorie intake further and have nowhere to go.

Not just fat loss

Although your body will use fat for energy when you're in a calorie deficit, it will also unfortunately use muscle too. As muscle cells require more calories to maintain themselves than fat cells, this change in body composition may result in a lower metabolic rate, meaning you may burn even fewer calories.

Important! This is why exercise – especially weight/resistance training – is so important to do alongside losing weight, as it helps to maintain lean muscle.

Hunger signals shoot up

When the body senses its energy stores (i.e., fat tissue) depleting, it decreases the production of a hormone called leptin. Leptin is the signal that tells the brain to stop eating, giving us a feeling of fullness and reducing our appetite. At the same time, the production of ghrelin (the hormone that makes us feel hungry) increases, meaning our appetites increase. This hormone response exists to help preserve our energy stores, and evolved thousands of years ago when food supply was scarce. Unfortunately, the process doesn't work the other way, so when we gain excess weight, our hunger signals don't switch off. This can make it especially hard to continue losing weight and maintain a lower weight following weight loss – our brains are literally fighting against us trying to stay slimmer!

Important! Again, this is why exercise is so important. It is something within our control – unlike our hormones. We know that exercise burns calories, and it also helps to build lean muscle (which burns calories), which can help keep your weight loss going.

Further metabolic slowdown

As previously mentioned, the term 'starvation mode' is an over-exaggeration, but there is some truth that cutting calories drastically and losing weight fast makes the body very efficient in expending energy, especially when it thinks it's losing energy stores. The scientific term for this is 'adaptive thermogenesis' but may also be referred to as 'metabolic adaptation' or 'metabolic slowdown'. Research is still ongoing to understand the biological processes that underpin metabolic adaptation. It's the downfall of many crash diets – losing weight rapidly sets your body up for failure, with some studies showing the effects stick around more than a whole year after weight loss!

Other factors affecting weight loss

Weight loss plateaus only really develop after a significant amount of weight loss or time – at least around 6 months in. If you feel as though you've hit a wall but it's only been a matter of weeks, there may be other factors at work - including water retention, hormone fluctuations, exercise-induced muscle inflammation and repair, certain medications, a bout of illness and bowel habits to name a few.

Woman exercising

'Strength training helps maintain lean muscle which is important for a healthy metabolism'

5 tips for when you hit a plateau

My top advice? Don't be surprised if it happens – it's a very common experience when trying to lose weight, so expect it then you won't be phased! Although it may feel like you are battling with your body, there are definitely things you can do to get things moving again!



1Increase protein and fibre

These two nutrients help us to feel fuller for longer, helping to manage appetite and reducing the temptation to snack throughout the day. Additionally, protein is essential for muscle growth and repair, so it may help to reduce muscle loss when losing weight. A diet high in fibre has been associated with improved heart and gut health.

Sources of protein include: meat, fish, eggs, beans, pulses (chickpeas, lentils), nuts, seeds, dairy products (milk, yogurt, cheese), protein bars and snacks labelled 'high in protein'.

Sources of fibre include: fruit, vegetables, oats, wholegrain starchy carbs (brown bread, pasta, rice and crackers), quinoa and other grains, nuts, seeds, beans, pulses (chickpeas, lentils), lower-sugar cereal bars and snacks labelled 'high in fibre'.

2Decrease your glycaemic load

Glycaemic load (GL) or glycaemic index (GI) are terms that refer to how much and how quickly sugar is released into the body following a meal. A diet higher in foods with a lower GL (green leafy veg, most fruit, beans and pulses, low-fat no-added-sugar dairy) may help to decrease hunger pangs compared to higher GL foods (white rice, white bread, potatoes, sweets, biscuits, cakes). You should be able to gauge the GL of your foods with a quick internet search.

3Decrease energy-dense foods

Foods that contain lots of calories per gram are energy-dense, so choosing foods with a lower energy density (fruit and veg) helps to bulk out your portion sizes and keep you feeling full.

4Increase exercise energy

Ramping up your activity levels is a great way to complement weight loss. Make sure you include strength-based exercises – these may not give you as much of an instant calorie burn as cardio, but they help to build and maintain lean muscle tissue, which can help you burn more calories even when you're resting!

5Increase energy flux

'Energy flux' refers to the flow of calories going in and out of the body. According to some research, a higher energy flux, so eating more calories and burning more calories, might help more with weight management than eating less and moving less, possibly due to the positive effect on muscle mass and thermic effect of food. For example, even though both could mathematically result in weight loss, eating 1800 calories and burning 400 calories through exercise may keep your metabolism higher than eating 1400 calories and not doing any exercise.

What about eating 6 small meals a day? Will that help keep my metabolism up?

The short answer is no! This diet tip has been circulating in the weight loss industry for some time – 'if you eat more often, you burn more calories digesting your food and therefore keep your metabolism high'. While it's true that we burn calories digesting our meals (this is called the 'thermic effect of food'), it's determined by the nutrient composition of food, not how often we eat. And even then, the thermic effect of food only makes up a small portion of our overall calorie burn. You won't 'break' your metabolism by eating your normal three meals a day, or even skipping a meal on occasion if you're pressed for time. In fact, intermittent fasting approaches are emerging as a potentially effective weight loss approach for some people. If you prefer to eat smaller meals, that's absolutely fine, but if you're only doing it to avoid 'starvation mode', think again!

Nutritionist Amy Wood (ANutr), MSci BSc Nutrition has a keen interest in the relationship between diet and health. Having been published in the European Journal of Nutrition, Amy is passionate about making evidence-based nutrition accessible to everyone and helping others to adopt a food-focused approach to taking control of their health.