I’m not usually a fan of prescribed “diets”—I live by more of the anti-diet mantra. Call me jaded, but the word “diet” has a bit of a negative connotation these days, with “fad” and “restrictive” usually preceding it. So, when I had the chance to give Dr. Axe’s new Keto360 program a two-week test run, I did some serious digging on the ketogenic diet and whether it’s healthy.

Here’s what I learned about the keto diet: You essentially swap a high-carb diet, which most Americans tend to eat, for a diet that’s very high in fat (the healthy kinds), moderate in protein, and very low in carbohydrates. The idea is that you change the source from which your body gets its energy (and burns calories) from glucose (from carbohydrates) to ketones (from fat). This shift doesn’t happen after one bulletproof coffee, though. It usually takes a few days of eating this way for your body to reach ketosis—where it’s looking to fat as its first source of fuel. Once there, though, your body “will be burning fat all the time,” says Dr. Axe. “It doesn’t matter if you’re working out or sleeping, or what you’re doing, your body continues to burn fat in ketosis.”

Armed with the 411 on how the keto diet works, I felt encouraged and relieved. The concept is rooted in nutrition- and weight-loss science. And from my initial conversations with Dr. Axe, I liked knowing that ketogenic diet results are always meant to be time-bound—eating this way is not a lifestyle and that makes sense. You may have heard that the keto diet was ranked last in the U.S. News & World Report’s 2018 list of the best and the worst diets. While I embarked on this journey before that news came out, I would have given the keto diet a try regardless. Part of the criteria for that ranked list was whether a diet was sustainable and easy to follow—the keto diet is neither, but it’s not designed to be. “I don’t recommend people follow strict ketogenic diets for their life,” says Dr. Axe. “I recommend 30- to 90-day periods, and after that moving into more of a ‘cycling’ phase, where you can cycle in and out of keto.” Dr. Axe admits that following a keto diet will be difficult for most people, since many Americans have diets high in sugar, salt, and carbs. But he says that the potential benefits—boosting brain health, supporting muscles and overall improved performance at the gym, at the office, and in life—are worth putting in the hard work. (Just Look at the Keto Diet Results Jen Widerstrom Saw After 17 Days.) 

All of that said, I was ready to put the keto diet to the test—and in the weeks between Thanksgiving and Christmas, no less. I relished the idea of proving that eating fat doesn’t make you fat—a diet myth that I’d like to see die a faster death.

The Prep Period

All new habits need a plan. Luckily, I had the Keto360 Blueprint (which mapped out how this was all going to go down), Dr. Axe at my disposal for ALL the questions, a Keto360-approved food list, and a husband who agreed to jump on the two-week keto bandwagon with me. (Research shows that having a buddy system will increase your rate of success in fitness, a diet, and even sticking to your New Year’s resolutions.) Still, sitting down to figure out my first week of keto diet meals and snacks was daunting. (Side note: I knew that if I was going to succeed at this, I’d have to be able to buy lunch. Luckily, Dr. Axe is totally on board, saying that most café salad bars will have what I need to create a keto meal—a big spinach salad with salmon and avocado, for example.)

Keto meals seemed so heavy and rich to me, and it just wasn’t how I was used to eating. Plus, I consider myself a flexitarian, so the thought of eating more meat—and more often than I typically would—gave me pause. Dr. Axe assured me that even vegetarians could pull off a keto diet if they planned well enough. (Vegans can, too.) That said, he’s a proponent of animal products and red meat specifically, because of the iron it provides for women (who are more susceptible to deficiency) and because it can bolster energy when carbs are lacking. (These Are the Other Things Vegetarians Need to Be Aware of Before Going Keto.)

Still, I enjoy cooking and I plan my meals on the regular anyway. With a keto food list in hand and advice from Dr. Axe in my mind, I filled my grocery cart with family-size versions of what I regularly buy (apples, berries, nut butter, kale), and a lot more meat than I ever have in my cart at one time (ground lamb, chicken, REAL bacon). What was missing? Some of my usual high-carb items, like whole-grain English muffins, orange juice, butternut squash, and tortilla chips.

While I was feeling pretty confident about my ability to cut back on obvious carbs, I felt less sure about doubling up on my fat. This is one aspect of the ketogenic diet that I think a lot of people misunderstand. Keto is not just a low-carb diet, it’s a HIGH-fat diet, too.

I can tackle coconut oil and avocado just fine. But there was one thing about the next two weeks that was looming over me: the intermittent fasting (IF) Dr. Axe built into his program. (Not all keto diets include this.) On Keto360 you can choose from three different eating windows, and I went for the longest: noon to 8 p.m., which meant I wouldn’t be eating solid food until midday. I have an active fitness schedule, which needs fuel (and recovery) on a regular basis, so I was concerned I’d really miss my morning yogurt with berries and be left feeling hangry by 10 a.m. (Not to mention, some food pros feel the potential benefits of intermittent fasting might not be worth the risks.) Dr. Axe assured me that not only could I handle the IF, but that temporarily starving the body this way will allow it to heal. “When you’re fasting for a period of time, you’re essentially letting the systems of your body completely rest and recover.” And he’s right. This is exactly why sleep is the most important thing for weight loss and health, why there are such things as beauty night creams, and why rest days are crucial to meeting any fitness goal. The breaking down of food, the rapid turnover of cells, and the repairing of muscle tears all happen during rest.

Plus, it’s not like I couldn’t feed my body anything until noon. Low-carb keto drinks such as tea, water, and coffee were all options, and Dr. Axe suggested adding protein (such as his bone broth or collagen protein powders) to my liquids to help fend off hunger. So, throughout my two weeks, I experimented with Dr. Axe’s bone broth protein and collagen protein, as well as unsweetened nondairy milks such as almond and oat milk. I’ll cut to the chase on this one: While expert opinion is mixed on the bioavailability of collagen powder and its potential health benefits, through trial and error, I landed on coffee with oat milk and collagen peptides as my go-to morning brew. I also took some of Dr. Axe’s Keto Fire supplements in the morning. They contain exogenous ketones, which is a fancy way of saying bonus ketones my body doesn’t produce on its own.

With meals planned, research done, and supplements on hand, I was ready and excited for the challenge. Here’s a snippet of my two-week experience—and the keto diet results that came with it: 

Day 1: It’s 8:15 a.m. and my stomach is growling. It knows it’s time for its breakfast, and I’m depriving it. I blended my protein coffee and ran out the door. My first thought is that the vanilla flavor is a nice complement to black coffee. But toward the end of the thermos, I realize that no matter how you dice it, vanilla bone broth protein coffee is not the same as a vanilla blonde roast with skim milk.

Day 2: There’s a bagel shop less than a block from my office. I pass it every single day and never really think anything of it. Well, not today! The smell of the freshly baked everything bagels—and was that veggie cream cheese I smelled?—was wafting out the door as I walked by extra quickly. (Though I found out later that there is a way to have bread and still stay in ketosis.) 

Day 3: I’m tired AF. Like the kind of tired when you’re so exhausted you have to use your left arm to lift your right arm. Somehow, I pried myself out of bed to work out only to realize cardio has never been more hardio, so some chill strength training was going to have to do. (I Now Know These 8 Things About Exercising While On the Keto Diet.) Nonetheless, feelings of lethargy were to be expected, says Dr. Axe, who says days 2 and 3 were also the hardest for him the first time he tried keto. “Every body is different,” he assures me. “Some people feel better by day 5, others take two weeks.”

Day 4: Grabbing lunch out has been successful thus far. Today was some tilapia, zucchini, and yellow squash, and a kale and tofu side salad. I tossed on half an avocado for good fatty measure. Oh, and I notice that I’ve lost a pound already, which is definitely just water weight—carbs hold water so limiting them is a surefire way to release some fluid in your body—but nonetheless. Weight loss wasn’t my objective, but I doubt I’m alone in thinking, “I’ll take it!”

Day 5: As fate would have it, 3 p.m. rolls around and we get a message that there are cookies in the conference room. I have been snacking on keto-approved foods like Granny Smith apples (the tart green apple has way less sugar than, say, a red Gala), and full-fat cottage cheese with blueberries (where have you been all my life, snack?) with no real trouble with cravings. But just knowing there are cookies that I can’t eat makes me feel a little cheated.  (Though These Low-Carb Keto Desserts Help With That.)

Day 6: When I thought back to what I ate today, I realized that between my salad and my lamb burger, I ate an entire avocado. The Keto360 plan recommends no more than half an avocado a day, and most nutritionists would probably agree. While the creamy, green fruit is filled with a lot of healthy fats, which I need in excess to stay in ketosis, at 300 calories a pop, that can quickly add up. (One gram of fat equals 9 calories, opposed to 4 calories per gram for both protein and carbs.)

Photo: Instagram / @alyssa_sparacino

It’s true that calories are not the only thing that matters in your diet, but if you’re trying to lose weight (which is a major reason many people try the keto diet), being mindful of combining all those high-fat foods is important for success.

Day 7: Peak exhaustion set in back on days 3 and 4, but I rounded the corner and started to feel more like myself the last couple days. Now at the halfway mark, I feel like I’ve gotten this keto meal-planning thing down—even if the food isn’t everything I hoped and dreamed. (More on that below). Plus I’m able to effectively train the way I’m used to. Over the weekend I hit the barre, the bike, and the (kettle)bells, and it feels great. I have my energy back and then some. And I simultaneously feel lighter (down another pound) and stronger.

Day 8: I’m still struggling to find a morning beverage that I enjoy and that keeps me full, so I try flavorless collagen protein powder with my coffee plus a splash of macadamia nut milk. It still isn’t the same as a French press with cream, but it’s a win! On the solid-food front, I’m starting to get a little grossed out about all the meat I’ve eaten in the past week. It’s more than I’d normally eat in three times as long. Lamb burgers, turkey lettuce-wrap tacos, chicken salads. My digestion is off (even though I take probiotics every morning), so Dr. Axe recommends his Keto Digest supplements at lunch. They contain fat-digesting enzymes to help break down the extra fat and protein that my body isn’t used to consuming, and it helps.

Day 9: I caved. I was running out the door for a morning workout and I had a hefty spoonful of peanut butter this morning, but I was hangry, okay?! While I silently wonder if that’s enough to send me out of ketosis, there’s really no guilt (food should never make you feel guilty, IMO). I need fuel for my workout—period.

Day 10: I’m starting to get sick of the same foods that I know are safe bets. And the number of times I’ve Googled: “Is _____ keto?” is getting out of hand. I’ve realized that the only real gripe I have with the keto diet is that there are so many healthy, nutritious foods that you can’t eat while on it. (Maybe that’s why experts say you should give up restrictive diets once and for all.) Carrots? Sweet potatoes? Brussels sprouts? What vitamins and nutrients am I missing out on by leaving these foods off my plate?

Day 11: The women at the salad shop accidentally put bread in my bag even though I said no bread. I threw it out on my way out the door. Today is a sad day. In other news, my energy is still kicking, I’ve been keeping up with my workouts, and I lost another pound. (I kind of hate weighing myself this often.)

Day 12: Dr. Axe assured me from the beginning that I’d be able to stick to my usual kind of workouts, and I’m happy to report that I can keep up with my favorite boxing and cycling classes without feeling dead halfway through.

Day 13: I have a love-hate relationship with this intermittent fasting thing. I think it’s “working,” and by that I mean I’m losing some weight. (Plus, improved body composition and definition can come with weight loss.) When I ask Dr. Axe if I should attribute my success to keto or IF, he says both. “I would say 80/20 it’s more strongly in the favor of keto, but intermittent fasting does help as well,” he says. The fat-burning capabilities of keto have more strength behind it when it comes to weight loss, specifically, he adds, but the intermittent fasting can be great for digestion and just feeling good.

Day 14: Today’s the last day on the Keto360 plan, so naturally I wear my Body by Butter tank to my morning workout. The class incorporated heavy lifting circuit training and cardio bursts, and I felt like I could go for round two when it was over.

In the end, I’m pleased with my keto diet results both internally and externally. I lost 4 pounds in two weeks, gained some energy and efficiency with my training, and more often than not felt that I could see better muscle tone instead of feeling bloated or weighed down. While the ketogenic diet may not be my go-to on a regular basis, Dr. Axe’s final feedback was encouraging: He says because I’ve now had a successful keto trial run, if I wanted to cycle through some keto weeks (or even a month, next time), I’d be able to easily, potentially reaching ketosis even more quickly. While going full-force back on the carbs could derail me or anyone else who wants to keto-cycle, Dr. Axe says the odds are in my favor. “Ninety percent of the time if someone’s done it once, they will get into ketosis quicker and easier the next time,” he says.

In fact, he says my already somewhat balanced diet is part of why I didn’t experience the keto flu. (Some people report feeling sick to their stomach, irritable, and dizzy, among other flu-like symptoms, for the first few days or even weeks of keto.) People who transition from a very high-carb and high-protein diet to a high-fat diet are more susceptible to these rare but extreme symptoms, he says. This is why he says he built a Feast Phase—when you’re adding fats into your diet without really restricting your carbs—into his Keto360 plan as a way to ease your body into ketosis. “If someone is a fairly good eater, and they already do have a moderate amount of fat in their diet—not high fat but moderate—typically they’ll transition pretty well,” he says.

Many people may look at my side-by-side before and after pics and think, “She was fit before and she looks the same now.” (Isn’t it strange how differently other people see you versus how you see yourself?) But eating and exercise should always be about more than the aesthetics. How do your diet and fitness habits make you feel? Food is fuel (and recovery) for the activities you like to do most. If eating well means you gain some perspective, then ending up with a better butt is just icing on the cake. BTW, I can have cake now.

This article originally appeared on Shape.com.