Written by Nyomi Graef
Weight loss shakes, diet shakes, liquid meal replacements... whatever name we call them, no doubt they are quick, easy and convenient. But how good are they for weight loss and reversing type 2 diabetes?
A recent study, published in the Lancet, decided to find out. The study's participants were 306 adults across England and Scotland. They were all overweight or obese with type 2 diabetes, and for three to five months they went on a strict liquid diet of weight loss shakes.
So, what were the results? Kathleen Doheny from EndocrineWeb reported that the study found that: "an intensive weight loss diet, totaling about 825 calories a day, can send type 2 diabetes packing.”
With obesity and type 2 diabetes increasing worldwide, this appears to be great news. But are weight loss shakes a good long-term solution for these health problems? Well, this is debatable. Even with these advantages, these drinks have plenty of negative qualities. To name just a few, they are often highly processed sugary drinks with too many food additives, as opposed to natural/“real foods” (such as fresh fruit and vegetables) that many nutrition experts recommend we mostly eat. Studies have found that when people stop drinking the weight loss shakes, and stop the nutrition education and supervision from health professionals, most people regain the weight that they lost, and their diabetes returns.
What other pros and cons do weight loss shakes have? Read on.
What are some positive aspects of weight loss shakes?
What are some negative aspects of weight loss shakes?
Weight loss shakes have many negative qualities. Below are some key ones to be wary of. Do your own research on the topic for more, if you’re interested.
Weight loss shakes are not “real foods”
Two cornerstones of a healthy diet are 1) eat plenty of vegetables, and 2) eat mostly “real foods”. Real foods are natural/unprocessed/minimally processed foods. These include fresh fruit and vegetables, fresh fish, eggs, healthy unrefined cold-pressed oils, nuts, and seeds. For optimum health, many nutrition experts, including leading dietitian Dr Joanna McMillan and top obesity and diabetes expert Dr Sarah Hallberg, say that we should eat real foods. The healthiest eating patterns in the world are based around eating real foods. The traditional Mediterranean diet, for instance, is a testament to this.
Read the ingredients list on the packets of weight loss shakes. Notice that they look a lot like a multivitamin and mineral tablet mixed with, for example, sugar, milk/milk products, some sources of fibre, fat and protein, and food additives. Think this sounds reasonable? Think again. Here are some of the unhealthy and questionable ingredients often added to weight loss shakes:
Thus weight loss shakes can be highly processed sugary/artificially sweetened drinks with unhealthy trans fat, dubious quality sources of protein, and too many food additives. Such drinks are not real foods. How would our bodies react to eating too many “fake foods” – like many weight loss shakes are – for months or years?
How balanced weight loss shakes really are is debatable
The packets on weight loss shakes can claim that the drinks are nutritionally balanced, but are they really? A number of past and present leading health experts, including leading UK nutritionist Patrick Holford, say that as we are each biochemically unique. This means, among other things, that the amount of various vitamins and minerals that we each need every day for optimum health varies from person to person, and this variation can be substantial.
According to Holford, the recommended dietary allowances (RDAs) for vitamins and minerals don’t cover nearly every adult for optimum health; the RDAs are designed to prevent severe (not mild) nutrient deficiencies in most people. Does this matter? Yes. Mild nutrient deficiencies can cause many different health problems, from lack of energy to irritability, headaches, skin problems and much more. It depends on many factors, for instance which nutrients people lack, and how many of them.
People who often need more than the RDAs, for a number of vitamins and minerals, include people who:
So how accurate (and honest) are the shakes' packets that claim that these drinks are nutritionally balanced? For which people in particular? Those who eat a “perfect diet”, and are not too stressed, and don’t drink too much alcohol, and so on?
The nutrients added to weight loss shakes can be poorly absorbed
The nutrients added to weight loss shakes can be less well absorbed compared with other forms of these nutrients. For example, these drinks can contain added calcium carbonate and magnesium oxide. These forms of nutrients are less well absorbed (and cheaper) than, for instance, calcium citrate and magnesium citrate respectively. Most people are probably unaware of this, so is this why the companies that make weight loss shakes add the cheaper forms of these (and often other) nutrients? And is this important? Yes. Many of us don’t receive enough calcium and magnesium (among other nutrients) from our diets, so it’s important to have well absorbed nutrients.
Weight loss shakes vary substantially in quality/how healthy they are
Is that popular brand of weight loss shake in our supermarket healthy or unhealthy (or somewhere in between)? Are the type of fat(s) and protein(s) added good quality? Is the drink low in sugar? Are the additives safe if we consumed them for months/years? These are just a few questions that come to mind about the quality of weight loss shakes. With so many of these shakes to choose from, unless we have, for instance, a good checklist/nutrition knowledge in the area, many of us can be forgiven for not knowing which ones are better quality than others.
Weight loss shakes are impractical/unsuitable when dining out/eating meals with others
Thinking of eating out at a café or restaurant? Maybe enjoying a shared meal with friends or family? Weight loss shakes aren’t very practical nor suitable on these occasions.
Weight loss shakes don’t educate us about long-term weight control, and might only be effective short term
Taken on their own, weight loss shakes don’t help us learn about and select healthy foods when eating out. These drinks also don’t help us prepare, buy and cook healthy meals and snacks, nor learn good portion control – all vital skills for long-term weight control and good health. This makes the transition from drinking liquid “meals” to eating real foods hard for many people. The result? After stopping drinking the shakes, the lost weight is quickly regained; people often turn to quick and easy unhealthy fast foods and pre-prepared meals. This is because they are used to the quick and easy aspects of the shakes, and might lack the time, skills etc. to prepare healthy foods.
As briefly stated earlier, the Lancet study mentioned above found that both weight loss and diabetes reversal are possible when weight loss shakes are taken along with medical supervision and education from health professionals about healthy eating. But how long is the weight loss maintained after the medical supervision and education ends, and participants are not made accountable for their eating habits? Dr. Scott Isaacs is the medical director of Atlanta Endocrine Associates in Atlanta, Georgia, USA. He said that the weight loss shakes study found similar results seen in previous research, and in many clinics around the country. "Remission was closely related to the degree of weight loss at 12 months," noted Dr. Isaacs.
EndocrineWeb says that: "Dr. Isaacs has seen these results in his own clinic, as he has been providing a similar program for nearly 20 years." He has: ""... seen temporary diabetes remission rates similar to this study," ... However, he has an important caveat, noting that ''the vast majority of patients regain all the weight when they discontinue the meal replacement diet," ... and the diabetes returns quickly."
Leading US obesity and type 2 diabetes expert Dr. Sarah Hallberg said very low calorie (VLC) diets (so this would include VLC liquid weight loss diets) work short-term, i.e. for a few months. In fact they cause rapid weight loss. But when the extreme calorie restriction ends, the “quick drops [in body weight] lead to quick rebound”. Dr. Hallberg said, “In summary, they [VLC diets] work really well in the short term. The question is the rebound, and what’s going to happen long term.”
Weight loss shakes have a number of advantages. These include being quick, easy and convenient, and containing a variety of nutrients. But the drinks often can, and do, have many disadvantages, which can cause problems, especially when they are a key part of people’s diets. These disadvantages include not being “real foods”; often being high in sugar and artificial food additives; being highly processed; having poorly absorbed nutrients; and not educating people about portion control, meal planning, and healthy choices when dining out and eating at home. Good portion control and being able to select/prepare/cook healthy snacks and meals are vital skills for long-term health and weight control.
Weight loss shakes can lead to weight loss and the reversal of type 2 diabetes, among other health benefits, when taken under medical supervision and with appropriate education. But studies have found that when people stop drinking weight loss shakes and stop receiving help with their eating habits from health professionals, most people regain the weight that they lost, and their diabetes returns.
Key qualities of healthy eating habits include being low in highly processed foods and low in added sugar, but high in real foods. Real foods are natural/unprocessed/minimally processed foods, such as fresh fruit and vegetables. For good health and long-term weight maintenance, many nutrition experts recommend eating real foods.
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