17th February 2023

When to use meal replacement shakes

Do you wonder what the difference between meal replacement shakes and protein shakes are, or when to use meal replacement shakes, and how they can help you lose weight? Here’s everything you need to know!

Protein shakes are designed to boost your protein intake which can be particularly helpful on fasting days, whereas meal replacement shakes are intended to provide the nutrition of a full meal.

Due to being low-calorie and rich in nutrients, these shakes can be a convenient way to get a healthy, low-calorie meal on the go and assist in weight loss. But how exactly do they help in weight loss, what should you look out for, and when to use meal replacement shakes?

What to look for in a meal replacement shake?

Meal replacement shakes can be an effective way to lose weight, or help on your weight loss journey if you know what to look for. Avoid shakes high in carbohydrates, as they may spike your blood sugars and leave you feeling hungry shortly after consuming. Ensure your shake of choice is high in protein, healthy fats and fibre to keep you feeling full, and steer clear from artificial sweeteners. If you’re looking to use shakes for weight loss, it’s also important to be conscious of their calories per serving.

The Fast 800 Shakes follow the principles of a Mediterranean-style diet, and are:

  • Mostly below 200 calories.
  • High in protein with over 20g protein to keep you fuller for longer.
  • Contain a third of your daily fibre intake to assist in a healthy gut microbiome.
  • Have over 25 vitamins and minerals in each serving.  
  • Contain all natural ingredients.


“In 3 months I have dropped 16kg, the shakes have made my life so much easier. I travel with a packet so I’m never caught “starving” with no decent choices to make.”

Shelley, Shakes Customer

Available in the UK, Australia and New Zealand.


How they can help you lose weight

They may keep you fuller for longer: A common mistake when people switch to a low-calorie diet is not getting in the right nutrients to ensure they stay full and nourished throughout the day. Simply eating a bowl of lettuce for lunch might be low-calorie but it isn’t going to keep you full, and may lead to eating more unhealthy foods later on. Good quality meal replacement shakes to keep an eye out for will prioritise protein and fibre to help satisfy your hunger.

Their high protein content may assist weight loss: Protein leads to greater satiety, helps you eat fewer calories in the day, and has been associated with benefits such as reduced body fat, less belly fat, lean body mass, and improved weight maintenance.[1][2] 

They replace unhealthy convenience food: Meal replacement shakes are great for those busy days where you may otherwise reach for a carb-loaded sandwich or sugary snack bar. A 2015 study found that fast food consumption and our eating behaviours while we’re out and about, is a main factor for lower diet quality.[3] The convenience of reaching for a junk-food snack can be mitigated by having something like a meal replacement shake on hand; convenient, nutritious and in line with your weight loss goals.

They may help you lose weight faster: There are several studies that suggest replacing one to two meals per day with a healthy meal replacement shake may speed up weight loss. One study compared groups of those on a reduced-calorie diet versus a partial meal replacement diet and found that the latter lost 2.4kg more in three months than a calorie-restricted diet alone.[4]

They may prevent nutrient deficiencies: As meal replacement shakes are fortified with vitamins and minerals, they may prevent deficiency in essential micronutrients that are commonly seen in low-calorie diets.[5] They have even been shown to assist weight management in those with type 2 diabetes.[6]

When to use meal replacement shakes

A satisfying, on-the-go breakfast

Say goodbye to sugary cereal and carby toast, and choose an option that will keep you going until lunch. Shakes are ideal for days when you don’t have time to make a healthy breakfast from scratch, or if you leave the house early for work and don’t want to break your overnight fast before you leave. Measure out your shake into a shaker, using our convenient scoop that comes included, then just add water when you’re ready to enjoy it and shake!

A filling lunch that doesn’t require any meal prep

Our shakes are powdered so all you need to do is add water and you’ve got yourself a filling lunch: no prep needed.

The Fast 800 shakes are made with natural ingredients and come in various different flavours, such as vanilla, chocolate, strawberry and coffee, with whey and vegan options to suit all diets and tastes. Whether you’re on a diet to lose weight, or you just need a convenient lunch or breakfast, a meal replacement is a great thing to have on hand: you never know when they’ll come in handy. 

Boost the protein and fibre of your meals

Meal replacements can also be used on non-fasting days (days where you’re not following an 800-calorie plan) alongside a low-carb meal for added nutrients and to make you fuller for longer.

Experiment with recipes

Add nutrients to your desserts! Try using meal replacement shakes to make protein pancakes, turmeric lattes or chocolate mousse (all of these yummy recipes can be found here). A popular recipe among The Fast 800 team is our indulgently delicious 2-minute mug cake.

 A simple backup option

For the days when you’re caught without a healthy option available: a benefit of using a meal replacement shake in powder form, rather than pre-made bottles, is that our shakes packets are compact enough to keep in a desk drawer at work, a handbag or even a car. 

Note: The Fast 800 shakes are available in the UK, Australia and New Zealand, click here to go to the product shop.

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