How do meal replacement shakes work?

Meal replacement shakes might feel like they are a relative newcomer to the nutrition market. They have, however, been around since the 1980s, when health and weight loss on the go became a priority for those who might not have had the time to cook and eat full meals. 

These days, the focus of meal replacement shakes has shifted away from weight loss and creating a calorie deficit, in favour of adding nutritional value for people who need a convenient, flexible option. They are still used for weight loss, with high amounts of protein to keep you feeling fuller for longer, great for those of us on the go. 

Ultimately, the way that meal replacement shakes work depends entirely on what you want them to do for you, how you use them to supplement your existing nutritional and dietary needs, and your overall goals. They can be that flexible. 

What sort of goals can they help us achieve? 

  • Weight Loss: Meal replacement shakes are designed to replace a meal (the clue is in the name), and usually contain all the nutrients that you would need for a meal, but often with a much lower number of calories, making them an option for weight loss. 
  • Nutritious Snacks: We’ve all been there - 3pm rolls around and suddenly, the world is full of biscuits, donuts and other empty calories. Especially if you work in an office. Nutritional drinks and meal replacements usually contain high amounts of protein, keeping you fuller for longer without overloading you with calories. Most contain 200-400 calories (depending on whether or not they are pre-made or you make them yourself and then what you use to make it up - using a plant-based milk will add more calories per serving than using water.)
  • Muscle Maintenance: This higher amount of protein can help us with retaining muscle by aiding in muscle protein synthesis, but only if we link that in with healthy exercising habits and don‘t overdo it if you’re using a shake to replace whole foods. 
  • Considering Nutrition: If you’re busy all day, you might think that skipping breakfast or lunch is just a part of life. Not only can this have a negative impact on our metabolism and gut, it can also make us more likely to consume a lot more than we should at our next meal ‘to make up for it’, whether we intend to or not. This can have a solid impact on our mood throughout the day - no one wants to be hangry - but also on our macros, what we eat and the way our body stores and processes energy. Making up a quick shake in the morning will not only front load your nutrition for the day, it will also make you less likely to eat anything in sight by lunchtime. Plus, you can tailor your shakes for your own needs, so you’re sure to have something you enjoy! 

What types of ingredients might they include to achieve our goals?

Whilst you’re looking for the right meal replacement shake for you, there are things to consider which may alter how they work for you. 

  • Artificial Ingredients: The use of artificial sweeteners, thickeners and stabilisers can put certain meal replacement shakes high on the Glycemic Index, causing blood sugar spikes, whilst ingredients like Xanthan Gum can slow digestion to such a rate that it can cause faintness. Choosing a shake with all natural ingredients, whilst potentially having a shorter shelf life, will ensure that you know exactly what you’re putting into your body. 
  • Nutritional Information: To make the most of your shake, check out the nutritional information. In order to help you feel fuller, look for a shake with a protein content higher than its carbohydrate content, at least 3g of dietary fibre and added vitamins, minerals and essential fats, especially omegas 3, 6 and 9. 
  • Look for flexibility: Some meal replacements claim to be everything you need for a ‘complete’ meal, which means that you are unable to have different taste and texture profiles without disrupting the ‘balance’ of the shake. Look for a product which is lower in calories and carbs so that you can add extra fruits, oats or even peanut butter to change the flavours up and make sure your taste buds don’t get bored. 

Above all, it is important to remember that meal replacement shakes work as a convenient and flexible supplement. They are not a replacement for a healthy, varied diet. Whole foods contain specific enzymes, antioxidants and compounds which cannot be replicated in a shake. They cannot mend unhealthy eating habits and they are not a cure-all, your goals might require more proactive exercise, mindful eating, and other changes in lifestyle.