I must be on a roll- this will be my second entry in less than a week. Time will tell how well I can keep this up. Anyway, this entry is really a follow-up from my last entry. which was about the scary high prevalence of obesity in the U.S. now, and how it is likely to get much worse in the next 10 years.
Over the past week or two there have been a large number of magazine and newspaper articles about various weight loss plans for people whose New Year’s resolutions include weight loss; it must be one of the most popular resolution, since even I have been told by quite a number of friends that their number one resolution for 2020 is to lose weight;. in some cases, a few pounds (we endocrinologists would prefer to talk about kilograms, not pounds, but I am used to thinking in the metric system and talking pounds and inches, and such to most people). One woman told me with a straight face that her goal for 2020 was to lose 60 pounds (in my opinion, if she did that, she would be invisible). Examples of the newspaper articles include several from the NYT: “Make 2020 the Year of Less Sugar, written by Tara Parker-Pope (posted 12/30/2019); “Scam or Not- What is the Keto Diet and Does it Work,” written by Dawn MacKeen (posted 1/2/2020); “Vegan Too Strict for You? Try a ‘Plant Based’ Diet,” written by Ethan Varian (posted 1/2/2020).
So what’s this all about and are some diet plans better than others? This is a complicated subject, and here I will only offer a few opinions based on my 50+ years working with overweight people. You may want to check out some of my earlier entries regarding obesity, various diet plans, high fructose corn syrup, and so forth.
There are literally hundreds of diet plans out there, each one claiming to be the best way to lose weight. recent popular diet plans include the Keto Diet (really a variation of the Atkins Diet), the Paleo Diet (really another version of the Adkins Diet, the Mediterranean Diet, the Intermittent fasting Diet, the Vegan Diet, and the Plant-Based Diet. There are also commercial diet centers such as Weight-Watchers and Jenny Craig. A visit to any public library or bookstore will provide you with book after book “pushing” this or that diet plan. So, let’s forget about the hype for a moment and focus on what we really know about diet plans.
First, I am not aware of any solid data showing that any one diet plan is any better than any other in achieving durable weight loss.; 5-10 years out, regardless of diet plan (please note, not all current diet plans have been around that long), only a small percentage of people weigh significantly less than when they started the diet plan. For a long time I have told people I was going to write a book with the title “Doctor, I have already lost 2000 pounds, so why am I still fat?” It’s not really so funny, since that is what most people experience with diet plans- up and down, up and down.
Second, there are quite a few health professionals out there making careers out of their particular area of interest, but with little or no scientific support for their recommendations. For example, contrary to hat some “experts’ say, eating strawberries, which contain the sugar fructose, is no more healthy than eating the same amount of fructose that has been added to some other food. The body does not metabolize “natural” sugars in foods any differently than the same amount of that sugar added to food, if the amount of the sugars is the same (here I am not talking about some added benefits from some foods because of fiber content, etc.).
Third, I think that at the moment, the best diet advice out there is what the foodie, and writer, Michael Pollan has concluded: that in the absence of any firm scientific evidence to recommend one diet plan over another, we should, on an empiric basis, eat a mostly plant-based diet and not too much (if you are interested in all this stuff, I strongly recommend you read “Omnivore’s Dilemma,” written by Michael Pollan).
It seems to me that many people are looking for some magical plan that with little or no effort leads to permanent weight loss. I hate to disappoint them, but there is no easy way to lose weight, and keep it off or to prevent undesired weight gain without eating less and/or exercising more. Actually bariatric surgery has been shown to have more durable weight-loss benefits than any known diet plan (I am not endorsing bariatric surgery as the best way to lose weight and keep it off, except in certain situations). Remember that for most people, obesity is caused by genetics and environmental opportunity (easy access to lots of high-calorie foods and little physical activity). In my opinion, we should be focusing on diet (what we eat) and not on diet plans. Sorry for the bad news.