There was an interesting study published in the Journal of the American Medical Association (https://jamanetwork.com/journals/jama/article-abstract/2673150?redirect=true) this past week comparing different diets for obese individuals and their outcomes. The study was widely covered in the media, and it was interesting to note how differently the same study was reported:
- New York Times: The Key to Weight Loss Is Diet Quality, Not Quantity, a New Study Finds
- Los Angeles Time: Your DNA won’t determine the best diet to help you lose weight
- The Daily Telegraph (London, UK): Low-carb diets ‘no better’ than traditional focus on fat
Reading those three headlines in major world newspapers would not instantly make you think they were talking about the same study, and yet they were. Besides being an interesting statement on how the media covers health issues (They usually focus on stories that conjure fear, They disproportionately cover stories that show any negative effect of an herb or nutrient while ignoring studies of medication side effects, They report conflicting stories within days of eachother with little context – alcohol is good for you/alcohol is bad for you, I could go on and on), I do think this study had several interesting outcomes that are relevant for our health.
So first, what was the study about. The study was titled, ¨Effect of Low-Fat vs Low-Carbohydrate Diet on 12-Month Weight Loss in Overweight Adults and the Association With Genotype Pattern or Insulin Secretion – The DIETFITS Randomized Clinical Trial¨ and was completed by Christopher Gardner, PhD – who is the Director of Nutrition Studies at the Stanford Prevention Research Center.
The study took a group of just over 600 obese people without diabetes and randomly assigned them to do a low fat diet or a low carb diet for a full year. Before the study they did blood tests to determine if they had insulin resistance (an early sign of Type 2 Diabetes). They speculated that those with insulin resistance might do better on a low carb diet as they had problems with sugar metabolism. They also tested each participant´s genetic pattern, looking at certain gene markers that have been speculated to predispose someone to do better on a low carb diet or a low fat diet or to be neutral for diet choices.
Each person was instructed thoroughly on how to avoid carbs or fat (depending on what group they were in) and supported with classes and lessons on healthy eating within the parameters of the group they were assigned to. No one was taught to count or limit calories and they were told to eat until they were full.
The result of the study were that there was no statistical difference in which group a person was in. After a year, the 305 subjects on the low-fat diet had lost an average of about 11.5 pounds, while the 304 subjects who completed the low-carb diet had lost an average of 13 pounds. In addition, neither the results of the insulin resistance test or the genetic test made a difference in who gained or lost weight.
In his commentary on the results, Dr Gardner pointed out that the biggest difference for who succeeded and had the most weight loss was those who cut back on added sugar, refined grains and highly processed foods while concentrating on eating plenty of vegetables and whole foods.
The results are interesting and mimic what many Naturopaths have been telling their patients for years. It is more important what you eat than how much you eat, i.e. quality is more important than quantity. Here are my biggest takeaways from the study:
- Dean Ornish, MD has been promoting a low fat diet for decades while doctors like Barry Sears, MD and Robert Atkins, MD have argued for a low carb diet. This study shows that both options are viable for weight loss.
- One of the biggest takeaways is the importance of cutting out processed foods from any diet – sodas, crackers, cookies, white flour, white sugar, etc. These foods truly sabotage our weight. Michael Pollan, author of ¨The Omnivore’s Dilemma¨ once wrote that you could eat almost anything and stay at a healthy weight if you cooked it yourself. The problem arises when we get most of our calories from restaurants and premade foods.
- The lack of benefit of genetic testing was an interesting finding. Several companies have promised that they can help you personalize a diet that will work for you based on your genetic patterns. As we see from many genetic studies, we are still in the early stages of being able to use our genes for predicting health outcomes. Maybe as time goes on, we will be able to find genes that we can use to predict weight loss.
- The lack of difference of the two diets with the insulin resistance group was interesting as well. I would have predicted that these people would do better with low carb diet approaches. I guess it further speaks to the importance of eliminating processed foods as being paramount.
- The author noted that they purposely did not focus on calorie counting as other studies have shown that most people quickly abandon this approach. Our brains are set up to make us detest feeling deprived and having a calorie restriction quickly leads to this feeling.
- Those that had the greatest success were those who took the changes to heart. This is where the regular support groups probably helped the most. Dean Ornish´s low fat diet plan has always had support groups at the heart and I think this is crucial for overcoming the complicated psychological relationships that many of us have with food.
So if you would like to lose weight or just eat healthier, based on this study, I would suggest cutting processed foods from your diet and eating real foods like fruits, vegetables, whole grains, and clean meats. I wouldn´t focus on calorie counting as this usually does not work. Find a way to do some physical movement and try to find a supportive group (maybe even one other person) that you can do this with. The processed food and restaurant industries have created a system set up to make you gain weight, we need to take back our own power by learning to cook real foods for ourselves again. It can be done and it is an effort worth fighting for ourselves and our children. The solution can be as simple as doing what everyone did 100 years ago – cook your own meals in your own kitchen.
And in case your wondering, I thought the New York Times had the best headline, but the Los Angeles Times summarized the information the best of the three papers.