7 Things I Wish I Knew Before Starting the Keto Diet (2024)

A few years ago, I was about to get married and wanted to lose some weight. I was eating healthy and exercising but just wasn't seeing the dramatic results I wanted. I decided to switch things up and try the ketogenic or "keto" diet for a few weeks. I stayed on it for three weeks and lost 3.5 pounds, so I did lose over a pound a week. But there are definitely some things I wish I knew before swearing off carbs.

You'll Probably Feel Terrible at First

After a few days on keto, I developed the "keto flu," which happens when your body's electrolyte levels plummet. On the keto diet, it can be tough to get a good balance of sodium, magnesium and potassium since the latter two come mainly from carb-rich foods such as beans, fruit and potatoes. Keto flu has symptoms like brain fog, drowsiness, headaches and even nausea. For me, it felt like the beginning of a cold when your body feels physically heavy and exhausted—not fun at all.

You'll Need to Plan

One thing that's great about the keto diet is that you don't have to count any calories, points or macros—all you need to track is your net carbs (or your total carbs minus fiber). But if you want to avoid the nasty keto flu symptoms and keep your body running like it should, you'll need to include plenty of foods that are high in magnesium (like almonds, spinach and peanut butter) and high in potassium (like salmon, avocado and leafy greens). It's also important to make sure you're getting enough fiber, which can be difficult to achieve when you're cutting out things like whole grains, potatoes and fruit.

Most Health Experts Hate It

Most dietitians agree that keto is one of the worst diets, unless you have a specific health condition (such as epilepsy) and your doctor or registered dietitian has recommended it and is following you closely while you're on the diet. In fact, one gastroenterologist and gut health expert I spoke with believes that keto "decimates the gut" and could be dangerous for your overall health since poor gut health is linked to chronic disease, anxiety, inflammation and more. If you're dead set on going keto, it's important to make sure you're getting plenty of fiber from plant sources such as leafy greens, chia seeds, nuts and berries. According to current nutrition guidelines, women should be eating 28 grams each day, and men should be eating at least 38 g.

Your Cravings Will Be Intense

During my short stint on the keto diet, my cravings were intense. And they never really stopped. I craved carb-rich foods I love like french fries, fruit and warm bread, but I also craved things that I don't really even like or eat regularly (specifically: old-fashioned cake donuts and Sour Patch Kids). I can't explain this phenomenon, but I blame it on quitting carbs and sugar cold turkey. Plus, restricting foods can make you crave them more. So dreaming of carbs made sense since I wasn't really eating them on the keto diet. I even tried to make low-carb versions of my favorite foods, but they just weren't the same—zoodles will never be pasta, and cauliflower will never be bread (sorry, not sorry).

It's Different for Everyone

My partner and I tried keto at the same time and had two totally different experiences on the diet. He has Type 1 diabetes and experienced steadier blood sugar and improved A1C levels (don't go on a keto diet if you have Type 1 diabetes without advice from your doctor or dietitian). He loved the meat- and fat-rich diet, whereas I had to brush my teeth several times a day just to get the perceived taste of fat out of my mouth. I felt bloated and icky, while he felt like he had more energy and lost over 5 pounds in three weeks.

I also experienced some food-related emotions that I wasn't quite prepared for. I struggled with eating rich and fatty things like cheese, butter, cream cheese and red meat at most meals—in a way, it felt "unnatural" and like it "shouldn't" be part of my weight-loss plan. I had always tried diets that promoted foods like produce, lean meats and whole grains and dialed back on foods like red meat and butter, so it made me step back and evaluate my relationship with these foods. I now know that there's room for all foods in a healthy diet, but it was a little concerning that I'd demonized these foods and hadn't realized it until I was eating them each day. Turns out, I love butter, cheese and steak, and they're now in regular rotation in my diet—just in smaller quantities.

You Might Have Some Weird Side Effects

Like I mentioned above, I couldn't shake the feeling of my mouth being coated in fat (I know, yuck). Some other folks on keto also complain about a side effect called "keto breath." It's a temporary condition but could manifest as a metallic taste in your mouth or breath that smells like acetone. It happens when ketones are produced in your body from burning fat, and it's actually a sign you're in ketosis. But perhaps one of the most common side effects (besides keto flu) is tummy troubles. Dramatically decreasing your carb count, not getting enough fiber and/or increasing your intake of fat can result in major constipation, bloating or diarrhea. To keep things flowing smoothly, be sure to drink plenty of water and eat lots of fiber-rich foods.

You Could Gain the Weight Back

You'll likely lose weight on the keto diet, but the weight can pile back on just as quickly if you start eating carbs again. One reason that people on a low-carb or keto diet lose weight so fast is because they're shedding lots of water weight (our bodies store every gram of carbs with about 4 g of water). When you start eating carbs again, those water-weight pounds can creep back up. And for most people, it's not realistic to do keto forever since it's so restrictive.