Is The Keto Diet Scientifically Proven?
The internet is buzzing with anecdotes about the incredible benefits of a ketogenic (or "keto") diet. Nothing new there, then, as each year sees the rise and fall of a new diet fad, most amplified by the social media echo-chamber but with little to recommend them.
This time, however, it sparked my curiosity. Not just because I am a modestly overweight 49-year-old whose love of food and drink outweighs my desire to be skinny, and as a result, someone who has been on a diet every January for at least 20 years and now realizes she needs a miracle. However, due to the science behind it.
To begin, I learned about ketogenic diets from Ethan Weiss, M.D., a prominent UCSF cardiologist on Twitter whose scientific acumen I admire. If he believes in the benefits of ketosis, I should investigate further. After 20 years of January diets, my own experience suggested that nothing changed: you only lost weight if you ate fewer calories than you burned, and if you ate fewer calories than you burned, you were hungry. As easy as that. Could it be that a ketogenic diet was truly unique?
The principle, on the other hand, makes sense. The bizarrely named "ketone bodies" are actually molecules that serve as the body's natural backup fuel supply when glucose is in short supply. Normally, we only enter ketosis (where ketone bodies accumulate in the blood) when we starve ourselves for several days at a time – not just overnight or by missing a meal. Because the glucose has been depleted, our metabolism shifts to fat-burning, converting stored fat molecules into ketone bodies that can power our muscles and brain. Being in ketosis, then, appears to be an excellent way to burn fat. On the other hand, going days without eating doesn't sound like much fun.
However, it turns out that you don't have to starve yourself to enter ketosis. All you have to do is eliminate carbohydrates from your diet (not just refined carbs, such as sucrose or high fructose corn syrup, but all carbs, including complex carbs and starches too). When the body runs out of glucose, it must enter ketosis because the brain requires either glucose or ketone bodies to survive. So, no matter how much protein or fat you consume, the body must still convert fat to ketone bodies to keep you going.
A ketogenic diet is therefore any diet that causes your metabolism to enter ketosis. And the diets that are currently trending aren't the first or only ones to do so. It's been several decades since the Atkins Diet became popular – and I've seen firsthand the weight loss that some of my friends achieved on Atkins. The Atkins diet is a ketogenic diet because it eliminates carbs and replaces them with protein. The surprising finding was that Atkins followers discovered they were much less hungry than expected, implying that protein calories made you feel fuller for longer. Feeling fuller leads to willingly eating less and, as a result, impressive weight loss.
However, if the weight-loss benefits of Atkins came from reduced hunger due to the sustaining properties of protein, you won't get them unless you bulk up the protein component of the diet. However, it turns out that the reduced hunger is caused by the ketosis state itself. It doesn't really matter how you do it.
So the science holds up – at least theoretically, I couldn't find a flaw in the modern ketogenic diet. So, instead of my usual "low-everything" calorie-restricted January diet, I gave it a shot.
On 1st July, I weighed a hefty 196 pounds, which on my 5'0" frame equates to a BMI of 30 to 35 "obese". When I first started my keto journey, I reduced my carb intake by 5%. I couldn't believe I was on a diet as I ate rib-eye steak with chili butter for breakfast, along with scrambled eggs and cheese. If, like me, you believe that food must contain fat in order to taste good, you will find keto to be a simple regimen to follow.
I usually work out for 30 min a day on a Concept 2 indoor rowing machine, but to help with the diet, I increased that to 45 minutes, allowing me to row 10 kilometers (without leaving the comfort of the gym). That exercise probably helped my body get rid of stored carbohydrate faster than usual (your liver stores a lot of carbohydrate as glycogen, ready for quick release to power your muscles), and I was Nirvana within 48 hours (well, ketosis anyway). Using urine dipsticks, I was able to keep my ketone body level above 6 mmoles/litre, indicating "deep" ketosis.
And there it has stayed for a month, while I enjoyed the delights of burgers topped with brie, jumbo prawn salads with avocado and sour cream dressings and creamy pork stroganoff with zucchini ribbons. Three fat-laden meals every single day.
First, the advantages: after three days of ketosis, I discovered that I was never hungry. I had no desire to snack between meals (which is usually a big weakness), and over the course of a month I found myself thinking less and less about food – to the point where missing lunch entirely was something that could happen "by accident."