The Best Weight Loss Trial You Will Never See!
In my book, Your Best Health Ever: A Cardiologist’s Surprisingly Simple Guide to What Really Works, I make the point that we should be very careful with how we interpret nutrition, weight loss and health studies. Far too often we will read a decisive-sounding post about an observational trial. My favorite is the belief that eating animal products of any kind directly causes heart disease, but you can take your pick from hundreds of other examples. The bottom line is the same. Observational studies, ones that simply observe people in their normal activities rather than randomly assigning them to two different groups, cannot prove cause and effect. They can only point out associations, which may or not have a real causative relationship.
In the world of nutritional science, observational studies require someone to remember everything they ate, accurately document it in detail, and depends on the researchers to control for every possible variable. That’s a recipe for a poor study. In addition, there is no way to control for self-selection bias. My made-up example from the book is that an observational trial would likely show that people who eat at Whole Foods are healthier than people who eat at McDonalds. Seems straightforward. But it turns out, they are also likely to be more educated, in a higher socioeconomic class, exercise more, have more access to medical care, and hundreds of other differences that we cannot measure. In a nutshell, that is self-selection bias.
So, although it makes sense that Whole Foods is healthier, and we believe it to be true, an observational study cannot prove this. Only a randomized trial can hope to answer the question with scientific validity. Which leads me to the point of this article. When it comes to nutrition and lifestyle as medicine, there are two trials we need to see, but likely will never see.
APEVVV (Animal Protein Eaters Vs. Vegetarians and Vegans)
All good studies seem to need attractive acronyms. I did my best here.
Take 10,000 healthy individuals. Randomize them into one of three nutritional groups. All three groups will adhere to the following:
- Every meal is at least 50% veggies with very limited processed foods and simple carbohydrates.
- Encourage healthy fats with nuts, seeds, olive oil and avocados.
- Strive for 10,000 steps per day plus 150 min of moderate exercise per week
- Practice regular stress management and engage in healthy lifestyle courses
They will differ as follows:
- 100% Vegan: No animal products at all are allowed.
- Vegetarian: No meat is allowed, but eggs and dairy are allowed.
- Meat Eaters: Every meal allows for 1-2 eggs, 4-6 ounces of animal protein (beef, chicken, fish, etc.), plus unflavored dairy, yogurt and cheese.
Follow them over 10 years to see who lives and who dies, who has heart attacks and strokes, and who enjoys their life more. Now that’s a trial that will tell us something! Do you see how this differs from observational trials? Since the subjects are randomized, we eliminate self-selection. They don’t get to choose which group they will be in.
In addition, since we measure hard-outcomes like heart attack, stroke and death, there is no debate about what the results mean clinically. We aren’t measuring “surrogate” endpoints like cholesterol, blood pressure, and other measures that may or may not be significant in this specific circumstance. Heart attacks, strokes and death are ALWAYS significant!
Also, notice how weight loss is not mentioned anywhere. The focus is on health, not weight loss. They are most definitely not one in the same. The problem is that this trial will be very difficult and expensive to create. Without a drug company having a vested interest in the result, it will be difficult to find someone to pay for it, and therefore we are unlikely to see it in our lifetime. That’s even more of a problem with my second trial that we need to see.
HLVS (Healthy Lifestyle Vs. Statins)
If you have read my posts on statins, by now you are aware of the incredibly small benefits of statins in primary preventions (i.e. when used in people who have not had a heart attack). In general, they do not reduce your risk of dying, and to save one person from a heart attack we need to treat anywhere from 60-140 people for five years.
One of the most common arguments for starting a statin is, “It’s the best treatment we have for reducing your risk of heart attacks and strokes.” My response? Not so fast. If I change that to say “It’s the best prescription drug we have for reducing your risk of heart attacks and strokes” then maybe I would agree.
What other treatments are better?
- Nourish your body purposefully.
- Move your body and exercise consistently.
- Manage your stress.
- Prioritize your sleep.
- Maintain strong social connections.
- Don’t smoke.
- And other healthy lifestyle actions.
Can I scientifically prove that these healthy lifestyle habits are better than statins? Not yet. That is why we need the HLVS study. Start with 10,000 people who have never had a heart attack or stroke. Half of them get a statin and “usual medical care” from their doctor.
The other half enroll in a lifestyle management program focusing on the following habits:
- Every meal is at least 50% veggies with very limited processed foods and simple carbohydrates.
- Healthy fats such as nuts, seeds, olive oil and avocados are encouraged with most meals.
- Appropriate proportion of animal proteins and animal products are allowed.
- Participants will strive for 10,000 steps per day plus 150 min of moderate exercise per week.
- Participants will practice regular stress management and mindfulness meditation.
- Sleep hygiene is repeatedly reviewed with each participant.
- Smoking cessation interventions are individually tailored to those who need it
They are followed for 10 years and we measure number of heart attacks, strokes and deaths. We also record subjective measures of happiness, depression and enjoyment of life. Then we will know. Are lifestyle interventions just as good as, if not better than, statins for primary prevention of cardiovascular disease?
I’m pretty sure I know what the answer will be. But alas, we will never see this trial either. Can you imagine if a drug company sponsored this trial and it showed the drug was inferior? Stock prices would plummet, and people will lose their jobs left and right. So, if we want to fund this trial, we better start our fundraising now (no bake sales or girl scout cookies please).
Conclusion
Does this mean we must disregard all nutritional and health science that isn’t a randomized prospective trial? That would mean throwing out most of our science. I don’t recommend that. Instead, we need to be vigilant about understanding the limits of the science and the limits to the catchy headlines. When we read a headline that “the Mediterranean diet has been proven to be better than statins,” we have to pause and think. We know that it may be intriguing, and we may want it to be true. However, until there is a head-to-head, randomized trial, we cannot prove that. Anyone who claims otherwise is inappropriately twisting the data.
What can we do instead?
In the absence of the trials that we need, we can continue to live our lives emphasizing healthy lifestyle habits. We can continue to demand a thorough and realistic explanation of the benefits and potential risks of prescription drugs. We can continue to seek out reliable and credible sources of information. And we can continue to talk about the need for better science. If we do this enough, we will transform ourselves for the better, and maybe, just maybe, we will change the world of nutritional and health science for generations to come.
Thanks for reading.
Bret Scher, MD FACC
Cardiologist, author, founder of Boundless Health
www.DrBretScher.com
Action Item:
Next time you hear a news story about a health study, take the time to look up the study and read it. Then you can decide, is this high-quality evidence? Does it apply to me? You may not understand everything, but the more you read, the more you will understand. And if you still have questions about it, ask me! I welcome your emails: info@drbretscher.com