"Due to the mountain of evidence supporting low-carb diets, since 2012 I have followed one to manage my own type 1.5 diabetes — which has characteristics of both type 1 and type 2 diabetes. And I have helped countless patients do the same. If many of my patients and I consume more than 50 grams of carbs a day our sugar goes out of safe range, no matter how much we exercise — and I am an avid runner."
If the committee moves forward with its potential “low-carb” definition in the upcoming 2020 guidelines, it will be a grave misstep. Labeling a diet that derives nearly half its calories from carbohydrates as “low-carb” is not only unscientific, it’s dangerous. Folks who follow this recommendation won’t see any of the benefits of a true low-carb lifestyle. Their health will continue to deteriorate — and they’ll dismiss “low-carb” diets as ineffective. - Dr. Mark Cucuzzella
Like Dr. Cucuzzella, I've been low carb (and intermittent ketogenic) since 2012, I've not strayed from the <20% carbohydrate percentage over the last 8 years, other than a short 4-6 month stretch. Low carb diet is an effective tool for many metabolic issues, psychological issues, and athletic performance improvements. There are many reasons to eat low carb and very few not to.
Now the USDA is considering adding low carbohydrate into its dietary guidelines. However, the USDA considers low carb 45%. No, that's not a typo. And yes, if you follow this page you probably know enough about nutrition to know that at 45% you are receiving zero benefits but perhaps the equivalent of tossing gasoline on a fire.
Eating a lot of carbs with a lot of fat? You have the macro nutrient equivalent of a birthday cake or a Twinky or a cheap low quality ice cream (high quality ice creams actually aren't all that sweet and are somewhat nutrient dense). The funny thing, I noted above a short 4-6 month or so stretch I was likely not low carb, I'd guess in that time I was no more than 30-35% carbs based on what I was eating in excess (mostly potatoes and ice cream). I won't take full credit for the dietary miscue, it was mostly medication induced, like a rodent to a salt wheel. Carbs were really good, and sweets were even better.
Now, before you panic, go back a few post on the CRC Facebook page to 2016 where I note that it's entirely possible to do quite well on a high carb diet in the absence of fat. The problem is, you can't mix the two. You can't have a high fat, high carb diet. This is called a high energy diet, and it's the absolute worst case scenario. No study has ever shown a high energy diet to be good for health, longevity, weight loss or any positive biomarkers. Basically, you are going to get fat and die. Eating Twinkies, milkshakes and cake are bad for you. No one is going to dispute this in a way that is sane.
Dr. Cucuzzella makes some great points, and he's a real practicing MD, so he's seen low carb work in the real world on real people. He's also an athlete whom I've heard on multiple podcasts over the years, dating back to the days when I was a trail runner. Click the link and see what all the fuss is about.