Are meal replacements a good option for those who want to shed the pounds quickly? Dr Sarah Schenker weighs up the pros and cons to using meal replacement products as an aid to weight loss
The popularity of the meal replacement has soared in the past few years. There’s many big brands on the market competing for top spot and although there are some subtle differences between them, ultimately, they all do the same thing and replace one, some or all your meals with a low calorie, nutritionally fortified shake, soup or bar.
Why meal replacements?
Quite simply, meal replacement products offer a way to control energy (calorie) intake, taking away the worry about what to eat. They control portion size and calorie content of usual foods. The most popular method is to use a meal replacement product (MRP) to replace two of your meals, usually breakfast and lunch, and then have a low calorie, balanced evening meal such as chicken, new potatoes and green veg or a calorie counted ready meal. This type of plan typically provides around 1,200-1,400 calories each day.
“Meal replacement products offer a way to control energy (calorie) intake„
How much weight can you expect to lose using meal replacements?
As with any reduced-calorie diet, the amount of weight lost will depend on the number of calories consumed, how much excess weight there is to lose, and, to a lesser degree, the amount of daily activity being performed. In general, an intake of 1,200 to 1,400 calories a day, should result in a weight loss of around one to two pounds a week.
Some plans are very low calorie and recommend that all meals are replaced with an MRP. This can cut daily calorie intake to 1000 or lower and result in a greater, more rapid weight loss, but as attractive as this may seem, it’s hard to stick to. Giving up normal meals can be boring and socially isolating so not usually something you can do in the long term. In a bid to maintain compliance (and customer appeal), some brands allow one or two small calorie counted snacks per day and most will provide information on a healthy lifestyle, including changing eating habits and becoming more active.
“MRPs are nutritionally balanced with a range of added vitamins & minerals„
Are meal replacements healthy?
By law, meal replacement products must provide the recommended amount of nutrients needed for good health and their composition must conform to certain standards defined by a European Directive. According to this Directive – the guidelines for which are based on research looking at the nutritional needs of dieters – meal replacement products must contain between 200 and 400 calories, at least 25 per cent of the recommended daily amount of protein and 23 vitamins and minerals.
Common ingredients of meal replacement shakes include skimmed and whole milk powder, soy protein, inulin, sucrose (sugar), vitamins and minerals and flavours such as cocoa and vanilla. The shakes usually come in the form of a powder which is made up with milk or water. The milk powder and soy provide protein and the inulin is a type of fibre; these are the two ingredients that promote satiety and feelings of fullness.
What does the science say?
Scientific research has shown MRPs are effective for weight loss. Several studies have compared the use of meal replacements with traditional calorie-counted diets and found the MRPs are just as successful in terms of helping people to lose weight in the short term. This is attributed to their convenience factor as there’s no need to think about food choices and counting calories. They’re a good option for those who don’t want or have time to plan and prepare their own meals.
Some studies suggest that meal replacements can help people keep their new lower weight. However, more research is needed to identify the suitability and effectiveness of meal replacement diets for ‘real-life’ situations and for people who have relatively small amounts of weight to lose.
Are meal replacements useful to lose weight in the long term?
One of the biggest criticisms with meal replacement diets is that they do little to help people change their eating habits or educate people about how to eat more healthily. A common problem is that returning to poor eating habits once a person has stopped using the products means the weight will almost certainly pile back on again. It’s recognised that MRPs are popular with those who want a ‘quick fix’ and making long term changes is not a priority.
MRPs are certainly not for everyone. Those who enjoy food or like to cook may find them boring and repetitive, especially as the range of products and flavours are rather limited. It’s also worth bearing in mind that your taste buds might quickly get tired of the same old flavours with the result that you end up craving your favourite foods. Unfortunately, cravings brought on by denial can quickly result in bingeing that in turn, causes many people to give up their good intentions.
What are other pros and cons of meal replacements?
While meal replacement products might be nutritionally balanced, there’s good evidence to suggest our bodies are better able to utilise the vitamins and minerals found naturally in food rather than those found in fortified foods. Also, MRPs do not provide the vast array of bio active substances found in plant based foods such as polyphenols. These substances are known to have antioxidant, anti-inflammatory, anti-carcinogenic and other biological properties and may protect from some diseases.
Following a meal replacement plan can be expensive and not suitable for those on a tight budget. In addition, most MRPs are not suitable for those who are lactose intolerant or suffer cow’s milk allergy as most of the products are milk based.
What’s the difference between meal replacement shakes and protein shakes?
Meal replacement shakes and protein shakes are not the same thing and there can be a big difference in the calorie content and the nutrient composition. Protein shakes often contain little or no carbohydrate, healthy fats or essential vitamins and minerals. Protein shakes are primarily designed to aid recovery and build muscle strength after exercise and are not designed to replace a meal. A MRP could be used instead of a protein shake post exercise but would probably be too high in calories.
While most people use MRPs to lose weight, for those wanting to gain weight or prevent weight loss, particularly that associated with illness, MRPs are a useful and convenient addition to a high calorie, high protein diet.
What do health professionals say about the use of meal replacements?
The use of MRPs for weight loss is approved by several health organisations including the British Dietetic Association and Dietitians in Obesity Management UK, as well as the National Obesity Forum. Many health professionals are willing to recommend them as an alternative method of weight loss to other more conventional dietary treatments. If MRPs are identified as being suitable for an individual’s needs, then it’s important that additional support and advice is provided to support behaviour change and prevent weight being regained.
In summary, trying a meal replacement plan may result in successful weight loss for the right type of person and are not associated with risks to health such as developing a nutrient deficiency as the products are close to being nutritionally complete. They often offer a good ‘kick-start’ to a new healthy eating regimen. However, for them to be successful in the long term, it’s essential the user understands what constitutes a healthy, balanced diet and learns to change their behaviour accordingly or they risk regaining the weight once they stop taking the products.
Dr Sarah Schenker is a registered dietitian, accredited sports dietitian and registered public health nutritionist. She is a media spokesperson and is co-author of the Fast Diet Recipe Book and provided the recipes for The Blood Sugar Fix, The Ageless Body and Eat Your Way to Lower Cholesterol. Her latest book is My Sugar Free Baby and Me. www.sarahschenker.co.uk