What’s the ‘best’ weight loss diet? Tough question right? I’ve been thinking a lot about this recently especially in light of some things I’ve read on twitter, blogs, Facebook, Tumblr… there are certainly a lot of opinions out there and everyone is convinced they’re right and that their diet is best/better/bestest!

Trials have been conducted (lots), but personal anecdotes seem so compelling, some have even established foundations to ‘prove’ that their theories as to causes of all [sic] obesity and diabetes - http://www.nusci.org/, http://nusi.org/ (note the subtle difference between these two websites and foundations, but with completely different dietary philosophies), http://thenoakesfoundation.org/ - there’s some big money (and big interest) behind this! There are also institutions who have their entire reputations at stake advocating for certain dietary approaches. What is so interesting is that few of these approaches seem to resemble the Food Guides, My Plates, Food Guide Pyramids from the respective countries in which these foundations, approaches, advice, etc say is THE way to eat. I mean if the experts disagree then what chance do the ‘mere mortals’ have?

Ockham's (Occam) razor is basically an axiom that in a sea of competing ‘theories’ (in this case dietary approaches to good health) the one with the fewest assumptions should be selected. The case may be that all of the approaches make assumptions? There appears to be enough evidence, from basic mechanisms, clinical trials, to support high fat/high protein, low fat/high fibre, high plant/high fibre or a multitude of other assumptions. But what’s missing, why are there so many ways to advocate for weight loss and good health? Could it be that multiple approaches work? Or are we just seeing crafted stories – Dr. David Katz (and his unnamed colleague) think so, at least in some cases. It seems, however, after conducting an in-depth survey (OK, it was a pretty shallow twitter question), that everyone (yes there are still some doubters) agrees that to lose weight – be it fat or lean – requires (yes I said requires) a negative energy balance. I know, hold on, it’s crazy but it’s true.

Many will talk about the ‘type’ of weight that is lost and I can certainly agree that fat loss should most often be emphasized over lean loss and it appears pretty clear that high(er) protein and exercise (particularly resistance exercise) are effective in this regard: http://www.ncbi.nlm.nih.gov/pubmed/21775530 (apologies for a gratuitous citation of our own work, there are many fine pieces of work in this area). But the fundamental truism is that E balance has to be negative and when you do that, and can sustain your new weight (likely by following the same approach you used to lose it) then you achieve success! But as we know the success rate of weight loss is not good (yes that’s an understatement) and yet every dietary best seller and concept that comes out has a new theory as to what it is that causes weight/fat gain and how to reverse it “Forever” and to “Forget everything you’ve ever been told” or that “What you’ve heard is all wrong.” I don’t doubt that there’s a shred of truth in everyone’s approach, but Ockham’s razor would suggest that there’s a really simple truth behind all weight loss programs and it really has to be whether you can stick to staying in negative energy balance to lose the weight and then stick to your new energy intake, eating less, forever… which as we know is a long time! So stick to it is what wins? Well I think that’s a big part of it.

It is said that those who do not study history are doomed to repeat it. What then of the Paleo, the LCHF, the high fibre vegetarian, the Real Food, Wheat Belly… well here’s a (brief) list of their predecessors and well know their fates: Scarsdale, Ornish, Weight Watchers, Dr. Bernstein, Herbal Magic, Cabbage soup, Atkins, Zone, South Beach, Raw Food, Mediterranean Diet, DASH, Jenny Craig, Sugar Busters, Flexitarian, TLC, Fruitarian, Cookie diet, Kangatarian, Hacker’s diet, Stillman Diet, Nutrisystems diet… you get the point. All of the aforementioned were called breakthroughs, revolutionary, and THE answer to losing weight and… yup keeping it off. And people still follow, swear by, adhere to, and ‘know’ these diets work. And for the people who stick to them they undoubtedly do. We also know, from the National Weight Control Registry that there isn’t one specific formula that promotes lasting weight loss. The one thing that does appear to be true is that whatever the folks who lost weight did to lose it then they have to keep doing it! A point recently made by Dr. Mike Joyner is that in his opinion “… the key to successful long term weight loss appears to be related to developing the skills and behavioral strategies needed to effect long term changes in diet, exercise and overall physical activity.”

I couldn’t agree more frankly and we’ve perhaps forgotten the lesson of how important cardiorespiratory fitness is. And thus, when considering the answer to the question of what diet works and works best, you have to take a step back and recall your history. All of the diets have a history of ‘success’ on an individual level and yet the number of people who are obese continues to rise. So, is your diet on this list and is it the best? If it works for you of course it is, but there’s not been any magic in any diet to date and I’m betting it’s going to stay that way. I do wish all of the folks who have started foundations to prove their diet is best, the best of luck (I actually hope they succeed). But I think they’re being a little naïve when they think they’re going to ‘cure’ obesity or type 2 diabetes with THE best diet, unless of course they’ve found that magic ‘stick to it’ juice? For the record, there’s no such thing as ‘stick to it’ juice!