What are they?
Weight loss or meal replacement shakes work removing calories by replacing one or more meals with a protein based supplement. They help to meet your protein and micronutrient needs while you eat fewer calories – and they are supposed to keep you full. In my clinical experience many people do find them satiating – but it all depends on the person and the product.
It’s important to understand what to look for in a vegan weight loss shake to make sure you’re getting the real deal and not just expensive protein powder.
In general, weight loss shakes fall into two categories:
Very Low Calorie Diets (VLCD) vs. Meal Replacement Shakes
VLCDs or “total diet replacement” programs work by severely limiting calories for a few weeks to rapidly initiate weight loss. VLCD products include shakes, bars and soups that are developed to meet 100% of your RDIS with fewer calories and carbohydrates than a meal. This puts you into ketosis (i.e. a starvation response that suppresses your appetite) making it easier to follow in the short term than straight calorie restriction. And the initial weight loss happens quickly, so your motivation stays high for a while.
While this type of diet is not sustainable long term, you can reset your baseline appetite and eating patterns and begin to form new habits.
VLCD programs are sometimes used to achieve rapid weight loss for medical procedures (such as bariatric surgery, transplants or dialysis). VLCD meal replacement shakes are the core component of “total” or “partial diet replacement” programs. They are regulated under the TGA in Australia and must contain at least 12g protein, 200-400 calories, at least 20g carbs and 25% RDI of vitamins and minerals. They also contain some soluble fibre- usually gums (e.g. inulin, pectin, guar, xanthan, etc.).
Meal replacement/ weight loss shakes
Meal replacements that are not claiming to be “VLCDs” aren’t regulated, and aren’t necessarily “complete” (i.e. they mightn’t have enough energy, protein and micronutrients to replace a meal). Actually, many of them are just protein powder. Meal replacements that have no carbs are NOT complete. The body needs carbohydrates to function properly, even if you’re trying to get into ketosis.
Weight loss shakes that don’t contain sugar (carbohydrates) are sweetened with non-caloric sweeteners. Since your body NEEDS and EXPECTS carbohydrates with every meal, this is a problem. Your cells expect to get glucose – if they don’t, you’ll overeat later to compensate.
In general, vegan meal replacements have at least as much protein as their dairy counterparts, and often they have adequate essential micronutrients. However, because they tend to be low or devoid of carbohydrates – they are not a complete meal replacement.
Do they work?
- VLCDs are effective for weight loss because they create a calorie deficit while delivering 100% protein and essential nutrients. However, while you can lose weight by using meal replacements, the psychological aspects of weight gain are not addressed.
- Perhaps counter-intuitively, low carb or no carb meal replacements are NOT ideal for weight loss. This is because carbohydrates ARE the body’s primary fuel source. Without carbs you’ll feel foggy, lethargic and hangry.
Are they vegan?
- VLCD weight loss shakes are nearly always made from dairy (i.e. whey or casein), so they are not vegan. Currently, there are no medical grade vegan VLCDs in Australia – however there are good quality meal replacements which can be tweaked. These include the Vegan Lady/ Man Shake and Nutrify, both of which need additional carbs to be complete. There is also at least one product from the US that meets the Australian criteria for a vegan VLCD.
Are they safe?
- Over 12 months people replacing 1 meal per day lost the same amount of weight as people on pure calorie restriction. So, if weight loss shakes work for you, and you like using them for convenience, etc., there’s no need to avoid them. As long as you’re otherwise eating a balanced diet.
- Weight loss shakes may lack fibre, so base your solid meals around vegetables and wholegrains.
- Keep track of how much vitamins and minerals are in products. Selenium, iodine, vitamin B6 and zinc have upper limits and can be toxic in large doses. Make note of how much of these are in your meal replacement and other supplements.
- It’s not recommended to do a total diet replacement for more than three weeks without medical or dietetic supervision.
How to choose a good vegan weight loss shake
- Look for a vegan weight loss shake with at least 2 different types of protein (e.g. rice and pea), or choose soy protein which is independently high quality.
- Avoid fancy ingredients such as probiotics or superfood powders. These are unnecessary and push up the price. “Fat burning” ingredients are not evidence based, and just take up valuable real estate.
- Choose one with about 20g carbs per serve if possible to mimic a real meal.
- Find one with at least 25% RDI of all the essential vitamin and minerals (especially especially calcium, iron, zinc, and iodine) and at least 18g of protein per serve.
- Choose one with fibre and less than 250kcals per serve when made with water.
- The words “nutritionally complete food” imply all of the above .
- There are some decent vegan weight loss shakes on the market. If they have no carbs, you can add a teaspoon of brown sugar or maple syrup to make it more complete.
- They can be a convenient meal on the go for those who are time poor.
- You must maintain the calorie deficit for the long term to keep the weight off.
- As they’re restrictive by nature, meal replacements shouldn’t be used by people with a history of eating disorders.
- If in doubt about whether vegan weight loss shakes are right for you, speak to dietitian for personalised advice.