If you thought meal replacement shakes were a throwback to the noughties, then this week's NHS announcement of plans to roll out a liquid soup and shakes diet, may have taken you by surprise. The plan for type 2 diabetics is aimed at reversing the disease and in trials, nearly half of participants went into remission after a year. It's especially pertinent now as we know type 2 diabetes and obesity increases the risk of becoming seriously ill with Covid 19.
Back in 2018, Dr Michael Mosley, creator of the Fast 800 Diet heralded the return of the meal replacement shake. It wasn't universally welcomed at the time, with memories of the 'fake food' shakes, often high in sugar and low in nutrients, not far from people's minds. It seems he was ahead of his time.
"Meal replacement shakes have been around for a long time as an aid to help people lose weight," he told us this week. "The reason the NHS has now decided to offer them to overweight or obese patients with type 2 diabetes is because of a recent large trial which showed that rapid weight loss (800 calories a day) led to long term benefits in those patients. They are carefully balanced to ensure you are getting adequate amounts of protein and essential nutrients such as vitamins and minerals.
"The main reason people use meal replacement shakes is that they are a convenient way to ensure that you are getting a low-calorie meal with all the essential nutrients. That said, you can do get similar results with real food, or by a mix of real food and a couple of shakes a day."
Nutritionist Kim Pearson , believes meal replacement shakes can be effective whether you have a large amount of weight to lose or just a few pounds. However not all shakes are equal, she adds. "As far as I am aware, the NHS has not stated which brand of meal replacement products they plan to work with and therefore it’s impossible to comment on the quality of the soup and shake products from a nutritional perspective. The quality of the meal replacement products is an important consideration as they can vary significantly. It’s not simply about a low-calorie diet alone, it’s about where those calories come from."
If you've ever tried a meal replacement soup or shake you'll know that they often taste iffy and can be quite high in sugar. Dr Mosley developed his own Fast 800 Shakes to be high in protein, low in sugar and generally more palatable.
Kim adds that expert supervision is key. "A qualified and experienced expert can tailor this type of diet to individual needs, dependent on an individual’s goals and state of health."
Is a meal replacement shake useful to shift a few pounds?
"Yes," says Kim. "Meal replacement diets can work well for those who just have a few pounds to lose. It’s important to differentiate between replacing the odd meal with a shake, and total meal replacement which is what the NHS is proposing. Both can be effective solutions, it’s about identifying what’s right for each individual. Everyone is different.
"They can be convenient when you need something on the go, or when healthy options aren’t readily available," says Kim. "I’ll often take them on planes with me and keep them handy when I'm travelling." Dr Mosley also is inclined to reach for a shake when he's filming when the only alternative is a chocolate bar.
What to look for in a meal replacement shake
Most reputable shakes which are sold as 'meal replacement' contain all the essential nutrients, says Dr Mosley. High protein low sugar is key. "Our shakes are particularly high in protein (42 per cent) and fibre (18 per cent) which will preserve muscle and keep you fuller for longer. You need at least 50g of protein a day to preserve your muscles and it is important to be low in carbs so your body quickly switches to fat burning," he says.
Kim agrees. "When looking at meal replacement products it’s important to scrutinise the quality. Many ‘low calorie’ meal replacements can be surprisingly high in sugar. Opt for a low sugar, low carb product that’s based on protein, providing a minimum of 15g per serving.
Will a protein shake do as a meal replacement?
Nutrient-packed shakes, whether they are for working out, for better skin or gut health have boomed in recent years. But just because something is a nutrition shake with a micronutrient list as long as your arm, doesn't make it a substitute for a balanced meal, unless it's labelled as a 'meal replacement shake'. "Meal replacement products have certain criteria placed on them in order to be classed as a meal replacement so that they're 'nutritionally complete'. A general protein shake wouldn't fit this criteria," says Kim.
But substituting a meal with a healthy shake now and then may not matter if the rest of your diet is good, as Kim explains. "If you're replacing all your food with shakes you need to get essential vitamins, minerals and essential fats from either the meal replacement product or additional supplements. If someone is eating a balanced diet and only using the odd shake here and there, they don't need those added nutrients because the food they're eating otherwise should provide the vitamins, minerals, essential fats."
She adds that shakes can be a useful nutrition top-up in themselves. "Many vegetarians and vegans I work with find protein-based meal replacement products a convenient way to help optimise their protein intake, too."
Who should avoid meal replacement shakes?
Total meal replacement shakes and soups are intended for people who are overweight or obese, says Dr Mosley. "They are not appropriate for people who are underweight or need to maintain their weight."
"Anyone with underlying health conditions, or taking regular medications, should check with their doctor before starting a meal replacement diet. If you’re pregnant or breastfeeding you should consult your healthcare professional before you start using meal replacement products. If you have food allergies it’s important to ensure the foods don’t contain ingredients you’re allergic to, " says Kim.
Is it better to fast than have a shake?
"The challenge with true fasting – when only water is consumed over several consecutive days – is that you lose muscle as well as body fat. Not eating means you’re not providing the body with essential nutrients and so there are a number of potential contraindications and side effects. A meal replacement diet provides the body with vital nutrients while still enabling fat loss."
She adds: "An approach like time-restricted eating [e.g. eating all meals within an eight-hour window] can be factored into a meal replacement diet approach."