Subtitles section Play video Print subtitles When you go vegan, does that automatically mean that you are eating a healthier diet? A lot of people wonder because there is such a thing as a junk food vegan. But overall, how are we doing when we ditch meat and we ditch dairy? My guest today wanted to answer that very question, so she and her team of researchers set out to do so. An incredible new paper has just been published. Our director of clinical research, Dr. Hana Kahleova is here to share her findings with us on The Exam Room. Dr. Kahleova, thanks so very much for being here. Thanks for having me, Chuck. Really interesting topic. I'm curious about this one because I think as we have seen this explosion of interest in eating a plant-based diet, we've also seen this explosion of products in grocery stores, a lot of which people would say, well, that's not necessarily healthy. So what did you guys discover in terms of when people go vegan? The effect that has on their diet. You're exactly right. You know, many people think, well, the vegan diet is just amazing. But what guarantee do you have when you go vegan that your diet will be healthier? Well, so we looked into the diet quality on a on a vegan diet. And let's explore what we found. Let me share my screen with you. Got it right there. Yeah. So we know that a vegan diet is amazing. It's great for your health. It's great for the animals and also for the environment. And yet, when we talk about the health aspects, many of the opponents of vegan diet say, well, but wait a minute, we cannot recommend to everyone to go vegan because they will eat a lot of junk food. So, you know, when when you go vegan, what guarantee do you have that that people will actually eat the healthy diet and not the junk? So this is something we looked into. How do you even define the diet quality? It turns out that there is a trend that the researchers at Harvard Medical School invented a tool that may be useful, which is called the Alternate Healthy Eating Index. All or the HPI. And they updated the index. So the updated version is from from the year 2010. And the idea is just let's give positive points to people for eating healthy foods and negative points for eating unhealthy foods. And the healthy foods are the fruits and vegetables and whole grains and legumes and nuts and seeds as sources of healthy fats and the unhealthy foods in this particular index are the red and processed meats, the sodas, the sources of trans fats, although they have been gradually eliminated, did come from our diet. There's still some processed foods that contain them and also also sources of sodium in our diets, such as cheese and olives and potato chips. So these would be the unhealthy foods. And we use this particular index when when, you know, when when people go vegan. So we conducted a randomized clinical trial and took 244 overweight adults. And we assign them randomly to either follow a low fat vegan diet that consisted of fruits and vegetables and grains and legumes for 16 weeks or the other half of the of the participants stayed on their usual diet for 16 weeks. And now we measured the diet quality using the alternate healthy eating index that I just described. And what did we find out? What happened to people who went vegan? What happened to their diet quality? It turns out that the diet quality significantly improved on the vegan diet by seven points, which was more than 10%. And this is good news, right? And we the the junk food was not necessarily forbidden on the vegan diet. We were encouraging them to eat to make the healthy options, but they were still allowed to eat it, eat sugar, for example, and eat processed foods and eat without any any attempts to improve their diet quality. The diet quality actually improved. This improvement in diet quality was also associated with their weight loss, their improvement in body composition because they were losing most of their weight loss was diet due to fat loss and also improvements in insulin sensitivity. So the improvement in diet quality had really implications for their cardio metabolic health and their weight management. Now the second question is when people switch to a vegan diet, when they start eating fruits and vegetables and whole grains and legumes, what out of these foods will tip the scales the most? That means which of the foods are most important for weight loss? Is it the foods that you don't eat that are the animal foods on a vegan diet, or is it the foods that you actually eat on a vegan diet? Which one? Which foods are the most important ones? And we found out there were two main predictors of weight loss on a vegan diet. While all of the foods are excellent that you that you eat on a vegan diet, fruits and grains and legumes and vegetables, all of them are great, but some of them seem to be more important for weight loss than others. So the number one predictor of weight loss was not eating any meat. No meat, no poultry, no fish. That was the number one predictor of weight loss. And the second most important predictor of weight loss was eating your beans, your beans and lentils and peas and all the legumes. So both are important, not only not eating the meat and the junk, but also eating the healthy stuff, particularly when it comes to beans that are a superfood. Based on our research study findings. That's a really interesting finding here, and I'm glad that you did this study. Couple of quick follow up questions for you. Number one, right away, I noticed that fruit juices were considered to be unhealthy at the time. A lot of people would say, well, orange juice. I drink that every morning with my breakfast. That's healthy, right? Why are fruit juices categorized as unhealthy for the purposes of this study? That's a great question. For this particular index, the researchers decided to group fruit juice among the unhealthy foods. But we can definitely have a discussion when you squeeze out their orange juice in the morning. It's much different from, you know, sugary drink that has only 12% of orange juice. So you need to be distinguishing between these. But generally speaking, there is a controversy. Another aspect to consider is that let's say you want to eat one glass of orange juice every single morning. One aspect to consider is that many people tend to overdo it with it with the orange juice. First of all, they don't usually drink the orange juice that's freshly squeezed. They buy it, you know, in a in a tetra pack. And that way, the nutrient content and also the fiber content is not so great. You would usually most of the fruit juices that you can buy in a grocery store are devoid of fiber. And yet you can you can find some brands that include the pulp. So those would include the fiber and would be healthier options. So there is a variety among the fruit juice products. The best ones would be the ones that you make at home, you know, freshly squeezed or even a smoothie where you put tofu fruit.