They claim to eliminate the faff of prepping meals, help with weight loss and provide enough protein and fibre to keep you full.
But meal replacements — which cost up to £9 a day — may not be as good as a home-cooked meal.
They can be a source of vitamins and an option for those who are short of time, notes registered nutritionist Rob Hobson.
However, food replacements, touted by the likes of Idris Elba, may not fill you up, can’t replicate vital compounds found in fruit and vegetables and don’t encourage healthy eating habits, he warns.
Here, Mr Hobson assess some of the most popular options.
Each drink contains 400 calories and can cost as little as £1.60 per shake, £3.04 for a ready-to-go bottle and up to £74 for a bundle of products
Huel
The popular meal replacement brand, backed by the Hollywood actor Idris, claims to offer ‘complete nutrition’ in each shake.
Since the Hertfordshire-based business was launched in 2015, it has sold more than 300million meals globally.
Huel is touted as a cheap, quick and convenient way of getting in a nutritious meal and its shakes are made from oats, peas, tapioca, flaxseed and brown rice.
Each drink contains 400 calories and can cost as little as £1.60 per shake, £3.04 for a ready-to-go bottle and up to £74 for a bundle of products.
‘This would be enough to provide the same amount of energy from a small or medium sized meal’, says Mr Hobson.
‘There is also sufficient carbohydrate, protein, and fat in this drink to constitute a meal and it has a good source of also has a good source of fibre as well vitamins and minerals.’
But Mr Hobson suggests it should only be used as a ‘temporary measure’.
Sold in a variety of flavours, the bottled shakes contain about 20g of plant-based protein and 26 vitamins and minerals.
The popular meal replacement brand is backed by the Hollywood actor Idris Elba
But there are some downsides to having an instant liquid dinner, Mr Hobson says.
Although the shakes have a ‘great reputation’ and can make it easy for those trying to lose weight to track their calories, it’s not as good as eating food.
He says: ‘None of these shakes will teach you how to eat a balanced diet (cooking, shopping for food, meal planning) though so I see them as a temporary measure and would say food should always come first.’
Mr Hobson warns against any liquid meal replacement because it can prevent you from feeling full.
‘Chewing slows down the eating process which means the body has time to recognise it is being fed helping to increase fullness’, says Mr Hobson.
‘Chewing also activates the vagus nerve which has a role to play in appetite regulation signalling fullness to the brain.
‘That said, the nutritional content of this drink will help to keep you feeling full as the fat, protein and fibre will take a while to be digested, contributing to fullness.’
Jessica Stansfield, nutritionist at Huel claims their shakes are different to others on the market.
She says it’s a ‘complete meal packed with all your macro and micronutrients, including complex carbohydrates, fibre and protein.’
Meanwhile, the high amount of protein in Huel will help you stay full as well as slowly releasing energy, she says.
Ms Stansfield adds: ‘Huel Powder has been tested externally and has a glycaemic index (GI) value of 16.
‘GI shows how a food affects your blood glucose level and a low GI is anything that scores under 55.
‘Foods with a low GI are good as they are digested slowly and thus raise blood glucose in a controlled and regulated way which may contribute to a prolonged sense of fullness.
‘We actively encourage healthy lifestyles, not just focusing on nutrition, but other day to day habits too where Huel can form a part of.’
Slimfast
Sold as a ‘tasty and balanced meal’, Slimfast shakes may not be enough to constitute as a meal replacement, suggests Mr Hobson.
The drinks which cost less than £2 a bottle come in flavours such as strawberry, chocolate, coffee and banana, contain 204 calories, 15g of protein and 23 vitamins and minerals.
But Mr Hobson is concerned this isn’t enough energy to keep you full for very long.
He says: ‘Technically, it would be good for weight loss as it is very low in energy, and it does have a good source of protein as well as containing fibre and a little fat.
‘However, I would be concerned that this is not enough to keep someone feeling full for very long and even more so if they have an active lifestyle.’
The shakes, which are backed by rapper Big Nastie, may not be enough to keep you feeling energised, which could lead to more snacking, Mr Hobson warns.
The shakes, which are backed by rapper Big Nastie, may not be enough to keep you feeling energised, nutritionists say. The drinks which cost less than £2 a bottle come in flavours such as strawberry, chocolate, coffee and banana, contain 204 calories, 15g of protein and 23 vitamins and minerals
He says: ‘I think the last thing you want when you are trying to lose weight is to feel hungry which may encourage snacking or failing to stick to your weight loss goals.
‘It’s also no replacement for getting in your five-a-day even though it contains plenty of fibre, vitamins and minerals.’
The five-a-day concept is about eating five portions of fruit and vegetables. Fresh, frozen, and canned all count towards it.
‘There are plant compounds in these foods that cannot be replicated in a supplemented product like this,’ Mr Hobson warns.
‘These foods also contribute to your daily fibre intake and the food matrix may help nutrients to be digested in a more efficient way than provided by a supplement product.’
Weetabix on the go
Weetabix doesn’t just sell its classic breakfast cereal. In a bid to create a breakfast suitable for those in a rush, it offers meal replacement shakes sold for £1.50 each.
They come in strawberry, chocolate and banana and contain 209 calories per bottle.
But even with 30g of carbohydrates, 4.3g of fibre, 8.5g of protein and six vitamins and minerals, Mr Hobson warns these are not enough to constitute a meal.
He says: ‘I don’t think there is enough in this shake to class it as a meal replacement. While its energy profile is like Slimfast it is lacking as much protein, and it is also high in sugars.
‘It also only contains six vitamins and minerals, and you would need more than this to pass it as a meal replacement.’
Weetabix on the go is sold in strawberry, chocolate and banana and contain 209 calories in each bottle
With 12g of sugars in a serving there is almost half the recommended daily amount.
NHS guidance sets the maximum daily intake at 30g of free sugars a day.
However, this limits only apply to free sugars — those added to products — rather than those found naturally in milk, fruit and vegetables. Eating too much sugar over time can lead to weight gain and tooth decay.
‘The fibre and protein are okay but there is a lot of sugar in this drink- almost half the recommended amount’, Mr Hobson says.
‘It does contain six nutrients such as B vitamins which help with energy metabolism and calcium for healthy bones but there are lots more essential nutrients required for good health.’
Although this shake would be a filling enough breakfast for some, especially if you don’t have much of an appetite, Mr Hobson says it wouldn’t be enough to keep you full for very long.
Plenny bar
The Plenny bar could be one of the few meal replacements that has a balanced nutrient profile, Mr Hobson suggests.
The bar, which claims to contain ‘all your daily nutritional needs’, comes in chocolate, salted caramel a cherry flavour to name a few.
It’s fortified with 27 vitamins and minerals it’s made from oats, soya protein, flaxseed and sunflower oil.
There are 400 calories in each £2.88 bar, 20g of plant-based protein, fibre and omega 3 and probiotics.
In each Plenny bar there is 400 calories, 20g of plant-based protein, fibre and omega 3 and probiotics for £2.88 each
‘This is one of the better ones’, says Mr Hobson.
‘It could be seen as a meal replacer with a bit more substance given the energy provided. It also contains a good source of protein as well as healthy fats, fibre and a full spectrum of essential vitamins and minerals.’
Mr Hobson suggests this meal replacement is better because it is in a bar rather than a shake and could aid digestion.
He says: ‘The vitamins and minerals found in shakes are normally readily absorbed. However, some nutrients may be better absorbed in the presence of other components of the whole food.
‘Then there is the chewing thing again as this signals the body to begin various digestive processes that aid digestion.’
Yfood, This is food
This is Food is yet another ready to drink shake that claims to be a ‘complete meal’, affordable and practical.
At £3.49 per bottle, it is not the cheapest meal replacement on the market.
But with 500 calories, 33g of protein and plenty of fibre, it is enough to be a meal replacement, according to Mr Hobson.
He says: ‘The product has been developed to contain high protein at the expense of carbs and a good amount of dietary fat. It also contains a good source of fibre and all the essential vitamins and minerals.’
However, it is one of the most calorific meal replacements out there and for many it could be ‘a little high in energy to meet their weight loss goals’.
In a £3.49 bottle there is 500 calories and 33g of protein which nutritionists say is enough to be a full meal
Instead, Mr Hobson suggests this shake would be good if you are looking for a convenient and quick meal.
He says: ‘It all depends on the individual and what their goals are.
‘An active person who is looking for a quick meal option on the go rather than cooking a meal may find this okay for breakfast. But if it was for weight loss, it may be a little high alongside other meals and any snacks across the day.’
However, yfood says it’s shakes are not designed for weight loss and made for when you need a quick meal that’s ‘ready-to-drink’.
A spokesperson for yfood says: ‘yfood is a great choice for situations where you don’t have time or access to fresh and healthy meals. We always encourage enjoying proper, home-cooked food but when this is not possible in our busy day, yfood is a good alternative.
‘Each bottle is a balanced ratio of nutrients and contains 26 vitamins and minerals as well as fibre and protein. We’re not about weight loss or cutting out meals, but instead, provide a balanced, convenient and tasty ready-to-drink meal when you need it.’
USN diet fuel
Advertised as a meal replacement shake, the chocolate ‘diet fuel’ contains 200 calories, 25g of protein and 3.4g of fibre, all at just £1 a serving.
But nutritionists say this is still not enough to be a full meal.
‘On paper it has all the right attributes to help keep you full such as being high in protein and a source of fibre’, says Mr Hobson.
‘It also contains a good source of all the key vitamins and minerals.
‘My only concern, like some of the other shakes, is that this is not enough energy to help keep you feeling full for very long especially if you are active.’
He also urges people to eat nutritious snacks, such as fruit and veg, alongside drinking these shakes because ‘you can only get so much into one shake’.
The chocolate diet fuel contains 200 calories, 25g of protein and 3.4g of fibre, all at just £1 a serving
‘The fibre content is about 10 per cent of the daily recommendation of 30g.
‘Fibre has many more health benefits than helping to keep you feeling full so I would advise all other meals and snacks contain a source’, says Mr Hobson.
Although Mr Hobson acknowledges that ‘everybody is different’ when it comes to weight loss and that shakes can be a short-term solution, he believes it’s always best to follow up a diet of shakes with a ‘sensible eating plan’.
This can help people understand how to plan and prepare a healthy balanced meal, he explains.
He says: ‘My personal view is that food should come first but I understand everyone is different.
‘Beyond weight loss I think these shakes may have a place occasionally if you have skipped a meal and it is not convenient to sit down to eat but they are usually very ultra-processed.
‘You could also make your own nutritious shake from whole foods.’
Optifast meal bar
Designed for weight control, the Optifast meal replacement bar is only 213 calories.
Sold for £17 for a box of six bars, it suggests by eating four of these a day it will provide you with all the essential vitamins and minerals an adult needs.
But Mr Hobson says he thinks this is more of a ‘snack’ than a meal replacement.
He says: ‘It does provide protein, fibre and the essential vitamins and minerals and gas been designed for weight loss as it recommends eating four bars daily as a total meal replacement diet.’
However, just eating these four bars a day is not Mr Hobson’s idea of an appetising way to lose weight.
He says: ‘To be honest, it does not look very appetising and if your day was structured around four bars, I think I would lose the will to live.
‘This versus a lovely brightly coloured salad with a bit of feta or shredded chicken on top would seem like a much nicer option.’
Sold for £17 for a box of six bars, it suggests eating four of these Optifast bars a day is all the essential vitamins and minerals an adult needs
However, these total replacement diets that see people eat bars and shakes instead of real meals, are designed for someone who is ‘very overweight and whose health is at risk’, Mr Hobson explains.
The meal replacement diets are advised to be done alongside groups sessions and other types of support.
For example, the NHS launched their soups and shakes diet as it recognised the need for something else to help support people to lose weight.
But for someone with a busy lifestyle these bars may not be enough.
He says: ‘I think you may struggle to support daily tasks especially if you have a busy lifestyle.
‘The body can pull on reserves of fat for energy, but its immediate source is glucose and your levels in the body would become quickly depleted.’
A spokesperson form Nestlé, which makes the meal replacements, say it understands meal replacements can be a ‘bog step’ from ‘conventional food’.
They say: ‘Optifast has a variety of meal replacements products that taste good and can help people with their weight goals.’
‘Optifast offers several diet plans to choose from, depending on individual goals and personal lifestyle.
‘Some products come as a bar, while others as a soup or a shake, which should be consumed as part of a varied and balanced diet and as part of an active and healthy lifestyle.
‘With the range of options, it allows the person to stay motivated and work towards their weight loss goals.’
The spokesperson adds: ‘Meal replacements are not intended to be used in isolation and are useful for their intended use only when part of an energy-restricted diet; other foodstuffs should be a necessary part of such diet.’
Protein Works
Protein Works rehydrated meals are closer to resembling a normal meal than many shakes and bars.
It has texture and savoury flavours, as well as being full of protein and nutrients.
The Thai curry sensation flavour contains 352 calories, 20g protein and 5.4g fibre, for £2.20 per meal.
‘This type of meal replacement may be nicer as it has something to chew and different textures which may feel more substantial rather than sipping a shake.
‘The flavours involved would also feel more like a meal over something with a sweet flavour like strawberry or chocolate’, says Mr Hobson.
‘It provides the elements you need in a meal replacement, and it may be better suited to some people than a shake.
‘This option provides more of a meal texture with the whole foods such as couscous which will offer a nicer texture’, he adds.
He suggests it contains the right amount of energy for a small meal, which would be good if weight loss was your intention.
‘It contains a good source of protein and fibre to help keep you feeling full as well as all the essential vitamins and minerals’, Mr Hobson says.
The Thai curry sensation flavour contains 352 calories, 20g protein and 5.4g fibre, for £2.20 per meal
But he believes it is a good option if you are short of time and need a quick meal. He suggests it will only supply you with enough protein to help support muscle recovery after training, though.
A Protein Works spokesperson says their ‘replacement shakes, complete meals, and savoury meals are an excellent source of nutrition for anyone who may otherwise skip a meal’.
But they do not dispute that it is incomparable to a home cooked meal but stops people from reaching for supermarket meal deals.
‘A scratch-cooked meal made with fresh vegetables and good quality protein that can be made in 30 minutes to an hour is always the best option’, a Protein Works spokesperson says.
‘But people have a lot going on and not everyone has the time or resources to do that every day, for every meal.
‘This is where our meal replacement shakes, complete meals, and savoury meals come in handy.
‘They’re a much better-for-you choice than skipping a meal altogether or turning to an unhealthy option – or a ‘meal deal’ that costs much more and delivers much less by way of nutrition.’
WHAT SHOULD A BALANCED DIET LOOK LIKE?
Meals should be based on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain, according to the NHS
• Eat at least 5 portions of a variety of fruit and vegetables every day. All fresh, frozen, dried and canned fruit and vegetables count
• Base meals on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain
• 30 grams of fibre a day: This is the same as eating all of the following: 5 portions of fruit and vegetables, 2 whole-wheat cereal biscuits, 2 thick slices of wholemeal bread and large baked potato with the skin on
• Have some dairy or dairy alternatives (such as soya drinks) choosing lower fat and lower sugar options
• Eat some beans, pulses, fish, eggs, meat and other proteins (including 2 portions of fish every week, one of which should be oily)
• Choose unsaturated oils and spreads and consuming in small amounts
• Drink 6-8 cups/glasses of water a day
• Adults should have less than 6g of salt and 20g of saturated fat for women or 30g for men a day
Source: NHS Eatwell Guide
