Meal replacements for weight loss: the pros and cons

What are meal replacements?

As the name suggests, a meal replacement is a product you can use instead of a meal, often to help with weight loss or to keep your weight steady. It is usually made to provide a set amount of energy, while still including key nutrients like protein, plus vitamins and minerals.

Meal replacements are used alongside everyday food. They are meant to replace one or two main meals a day, not every meal. The idea is to make it easier to reduce your energy intake while still getting the nutrients your body needs. For lots of people, meal replacements can also make day-to-day life easier by saving time and reducing the need for planning.

Who might meal replacements suit?

Meal replacements can be an option for healthy adults living with overweight or obesity who want to lose weight. They can also suit people who want to maintain their weight, for example after losing weight.

They are often used as support for a period of time, to help create an energy deficit or to reduce the chance of weight regain.

Different types of meal replacements

Meal replacements come in different flavours and formats, such as ready-to-drink shakes, bars, soups, and powders you mix with a liquid. That can make it easier to find an option that fits into your routine.

Ready-made drinks can feel convenient when you want something quick. Powders can be mixed as and when you need them. For some people, soups or other warm options feel more like a “proper meal”. Bars can be handy if you want something easy to store and take with you.

It’s worth telling the difference between meal replacements and other products like standard protein shakes, smoothies, or snack bars. Those products are not designed to replace a full meal. They are often made with different ingredients and can have a very different energy and nutrient content.

Can you lose weight with meal replacements?

Yes, meal replacements can help with weight loss and can make losing weight easier, because they typically contain less energy than a usual meal, often around 200 to 250 kcal.

Research shows that people who use meal replacements as part of a structured programme, on average, lose more weight than people who follow similar advice without meal replacements. In people with type 2 diabetes, studies have also seen positive effects on long-term blood sugar control (HbA1c), alongside weight loss.

At the same time, it’s important to remember that overall energy intake over time is what drives weight loss. A meal replacement can make it easier to reduce the energy in one meal, but if you end up eating more at other meals, or grazing between meals, weight loss may not happen. Long-term weight loss is rarely about one product. For results that last, meal replacements often work best alongside support with eating habits, behaviours, and lifestyle.

Pros of meal replacements when you want to lose weight

Convenient and easy to access: One of the biggest benefits is how simple they are. Meal replacements often need little to no prep, which can help if you find it hard to plan, shop for, and cook meals. They are also easy to take with you, and can be a practical option when you want a lower-calorie meal close at hand, like when you are travelling.

A way to get started: For some people, a meal replacement can be a way to get going and see results a bit sooner. That can boost motivation and make it easier to keep going with other changes to eating and daily habits.

Nutritionally reassuring: A meal replacement includes key nutrients within a lower energy intake. Many products are also relatively high in protein, which can help you feel full and support muscle mass during weight loss.

Less decision fatigue around food: You do not need to count calories, plan what to eat and how much, or make lots of food decisions. The portion is ready and the energy content is set in advance. For many people, that can make it easier to stick with a plan, especially during busy or stressful periods.

Can help with more regular meals: If you often skip meals or eat at unpredictable times, a meal replacement can make it easier to fit in breakfast, lunch, or dinner at more consistent times. It can be a helpful option when you might otherwise miss a meal or choose something less nutrient-dense.

Cons of meal replacements

One downside is that they can feel repetitive and a bit boring. Some people miss variety, enjoyment, and the social side that often comes with everyday meals. Some also miss chewing and the feeling of eating “real food”.

Meal replacements also do not automatically lead to weight loss. It can be easy to make up for the lower energy intake, for example by eating more at other meals or snacking between meals. If that happens, weight loss may not happen.

Another downside is that meal replacements on their own do not build long-term habits around everyday food. If you do not work on routines and eating patterns at the same time, it can feel harder to maintain weight loss when you go back to regular meals.

When should meal replacements be avoided or used with extra caution?

Meal replacements should not be used without a medical assessment if you have:

• an eating disorder, or a suspected eating disorder
• pregnancy or breastfeeding
• serious kidney, liver, or heart disease
• certain hormone-related conditions, or conditions where the risk of nutrient deficiency is higher

Combine meal replacements with activity and nutrient-dense food

Meal replacements can be used as support for weight loss, but they tend to work best alongside regular physical activity and a varied, nutrient-rich diet. Exercise supports health and can help maintain muscle mass during weight loss, especially strength training.

Because meal replacements are meant to be combined with everyday food, it helps if the meals and snacks you do eat are as nutrient-dense as possible. Try to include vegetables, wholegrains, and a good protein source, such as fish, pulses, eggs, or lean meat. That can help you get enough nutrients, feel satisfied, and build eating habits that still work when you are not using meal replacements.

Meal replacements as part of medical weight management

In some cases, meal replacements can be used as part of medical treatment for overweight or obesity. This is most often within structured programmes in healthcare services, where the aim is to achieve weight loss in a controlled way.

At Yazen, we may sometimes use meal replacements if there is a need, or if you are interested, as one tool within an individual plan. To offer an option that suits medical weight management, we have also developed our own meal replacement together with our dietitians. It contains more protein and less sugar than many other meal replacements. We have also reviewed the vitamin and mineral content to better match common needs, including extra vitamin D, as low vitamin D levels are especially common in people living with obesity.

Summary

Meal replacements can be useful support for weight loss and for keeping weight steady, for some people. They often mean you take in fewer calories, which can support weight loss. Meal replacements are used alongside everyday food and are only meant to replace one or two main meals a day, not every meal.

Used in a way that suits you, meal replacements can give structure and clearer boundaries around meals. For results that last, they often work best alongside nutrient-rich food, regular physical activity, and support with habits and lifestyle.

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