Read this review before trying the ketogenic diet.
Credit: Rimma Bondarenko

If you're reading this article you've probably heard something about the keto diet—the low-carb, high-fat way of eating that has been linked to better brain health and lower cholesterol, and of course weight loss (here's what our nutritionist thinks of it).

Also known as the ketogenic diet, it was originally created in the early 1900s to treat epilepsy, but the diet has recently blown up. And so, after several of my friends couldn't stop talking about how they lost weight, had more energy, and felt amazing, I decided to test the claims myself.

I also was intrigued by what I'd read on the diet's effects for folks with Type 1 diabetes (the kind you're born with). My fiancé, Nick, has to deal with all the pin pricks and blood sugar crashes that come with having Type 1, and isn't much of a dieter. But he decided to try the diet with me, and we gave ourselves a goal of three weeks—not forever, but long enough (I figured) to notice a difference.

Full disclosure: We had two totally different experiences.

The goal of the keto diet is to put the body in a state of ketosis, where the body is starved of carbs and sugar (traditional forms of energy) and has to begin breaking down fat for fuel.

Keto dieters are allotted no more than 20-50g of carbs per day, depending on their body weight, height, and lifestyle. I used a keto calculator app to determine that I should have about 20g net carbs a day, which is calculated by subtracting fiber from carbs (for example: a cup of eggplant has 4.8 carbs and 2.5g of fiber, so your net carbs would be 2.3g).

What We Ate

An extensive Google search revealed that many healthy foods we love and eat daily (such as yogurt, oatmeal, quinoa, beans, corn, and pretty much all fruit) were off limits. But, cheese, meat, ranch dressing, and green veggies all get a green light.

This feels really counterintuitive. What kind of diet lets you eat a double quarter pounder with cheese (sans bun), but not an apple?

Cooking Light’s Food and Nutrition Director Brierley Horton, MS, RD, is not a fan, so when I told her abut my plan, she suggested I give it a pass. “I’m cautious of any diet that eliminates entire food groups, such as fruit," she explained, "because you won’t be getting the key nutrients your body needs. It’s not a sustainable diet for the long run.”

I ignored Brierley for the sake of journalism (sorry, Bri!), and got to cooking.

Step one: I prepped several keto-friendly recipes for the week, and went shopping. One day I made a sheet pan dinner with sausage, Brussels sprouts, onions, mushrooms and herb butter. Another, I made kale salad with chicken, macadamia nuts, and lots of Parmesan. For lunches, I ate things like tuna salad-stuffed avocado. And to satisfying my pasta craving, I cooked zoodles with meatballs and low-carb marinara sauce. For my mashed potato cravings, I subbed in mashed cauliflower with lots of shredded cheese.

During the diet I also enjoyed steak, fish, and chicken, with a regular rotation of veggies. And eggs, oh my God, I ate SO MANY EGGS.

Credit: Jaime Ritter

Since things like butter and cheese weren’t “off limits,” eating on the keto diet was super flavorful, and finding options at restaurants wasn’t difficult at all (almost anywhere has protein and greens, or a salad with lots of cheese). A favorite of mine was the Five Guys bacon cheeseburger with a lettuce “bun.” I could feel Brierley cringing, but hey, it was at least delicious.

Our Weight Loss Goals

Here's the thing: It really does work for weight loss—we both lost more than a pound a week, while counting no calories, and eating all the butter and fat we wanted (more than I wanted, actually).  I lost about 3.5 pounds in the three weeks that I was on the diet (though I gained a bit back toward the end, as you'll see) and Nick lost more than 5 pounds, as well as gaining some other health benefits, which I'll talk about below. 

How We Felt

I had heard the transition to ketosis was supposed to be a little rough, but my friends all said they felt amazing after being on it for a few days, so I was unsure how I was going to feel. Unfortunately, it was more than just a little rough.

For the first few days I constantly had the grossest sensation of grease covering my mouth. I brushed my teeth at least two or three times a day to get rid of it. I blame it on all the extra fat I was eating from sources like butter, cheese, eggs, ranch dressing, fatty meats, and mayo. I also felt like there was no way I was losing weight—all the fat and dairy I was eating made me feel super bloated (in hindsight, I think it was all of the sodium.)

Then there was the worst part: The keto flu. The transition to ketosis involved a major energy drain caused from carbohydrate withdrawal. Keto flu hit me like a truck on day 2 and lasted until about day 4. During that time I felt super tired, achy, and slightly drunk. I was so foggy at work, I could barely concentrate. Nick had keto flu around day 3, and it lasted until day 5.

Our keto flu was coupled with intense carb cravings (after this diet, I truly believe the research purporting that carbs and sugar behave the same way as cocaine and heroin.) Let me tell you, we were SUPER fun to be around during that first week, and our text messages looked something like this:

Credit: Jaime Ritter

And guys, the sugar and carb cravings were so, so real. I wanted a cake donut so badly I would have thrown a rock through a Dunkin Donuts if I'd had the energy, and don’t really even like them that much—I know what's in them. Meanwhile, Nick was craving a smoothie. A smoothie! In the three years we've been dating, I’ve seen him eat fruit a sum total of two times.

On night three, I went to Bed, Bath & Beyond to pick up a wedding gift for a friend, and I saw an elderly man licking a soft serve ice cream cone. I had taken three steps toward him before I realized I was contemplating ripping it out of his hand, and knocking him down, just so I could take a bite. I had to turn around and leave immediately. I'm not proud of this.

I felt like an absolute monster, and immediately Googled “keto flu cures.” Turns out eating lots of potassium helps, as well as guzzling water, so Nick and I upped our intake of foods like avocado, leafy greens, and salmon, which helped tremendously (I didn't threaten any more old men.)

How Nick Fared

Nick lasted the entire three weeks, and had great success on the keto diet. Not only did he lose 5.3 pounds, but he had a far easier time controlling his type 1 diabetes. During the three weeks, he barely had to take any insulin on top of his basal (read: baseline) amount, which is incredible.

The day after we finished, he went to the doctor to get his 3-month average blood sugar percentage tested—what's called the A1C levels. Someone without diabetes will an a1c level of 5.7 or lower—but Nick’s usually hovers around 8 or 9, which isn’t great.

3 months ago, his A1C was an 8.6. He had it tested the day after we finished the keto diet, and it was 7.6—an entire point lower! That’s a huge deal for diabetics, and Nick credits a low-carb diet for the changes. He says he wants to stay on the keto diet because it’s helping him manage his diabetes better, plus he’s losing a good bit of weight on it.

How I Fared

I, on the other hand, did not last the entire three weeks—but, hear me out. I made it 20 days on the keto diet, but the final weekend I attended my best friend Holly's wedding.

I had been a perfect low-carb angel the entire wedding weekend. I pushed my mashed potatoes to the side during dinner, limited my cocktails, and made sure to eat lots of fat (gross, I know).

But Holly’s mom made her wedding cake—a gorgeous lemon curd and vanilla bean cake that was better-than-bakery quality. You could smell the bright lemon and creamy vanilla from across the room, and I knew that I was toast. I tried to hold strong when our server brought us all out slices, until Holly’s mom asked if I was going to try a piece.

She had traveled all the way from Ireland for her daughter’s wedding, and made the cake herself, and I just couldn’t resist any more—nor did I want to! I thought about it and decided that life’s too short not to eat the cake at your best friend’s wedding. So I ate every glorious bite of that carb-y, sweet cake, and I had zero regrets.

...that is, until I got super sick the next day. Apparently, when you give up carbs and sugar for weeks and then dive head-first into a massive slice of cake, your body doesn’t like it.

I’ll spare you the details, but suffice to say if you’re coming off keto, tread lightly. Otherwise, you’ll suffer.

Despite ending on a low note, keto wasn’t all bad. I was down 3.5 pounds until I had the cake, though I still ended up losing 2.8 pounds.

Plus, the diet forced me to become way more conscious of what I was putting in my body. I now realize that before starting keto, I was eating way too many carbs.

Though I realize there’s room for an occasional bagel at breakfast or a slice of wedding cake in a balanced diet, I definitely think I’ll continue cutting back on my carb intake. It was amazing—and kind of scary—to see the effect that cutting out carbs—and reintroducing them—had on my body.

Not all carbs are bad (in fact, you need carbs to live), but I realize that I was eating too much of the processed junk. So even though Nick and I had two very different experiences on the keto diet, I think we will both continue to eat more leafy greens, lean protein (we need a break from all the beef), and slash our carb intakes. And I think Brierley will be happy to hear that, too.