7 Things You Should Expect When Going Keto

Jessica Migala
by Jessica Migala
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7 Things You Should Expect When Going Keto

By now, you’ve heard a ton of buzz about the ketogenic diet. This high-fat, low-carb eating plan is popular, but can also be extremely divisive. Your coworker says he lost XX pounds — and eats all the bacon he wants. Your neighbor, on the other hand, said she felt so tired and stopped the diet after four days. If you’re thinking of trying keto yourself, you’ll best set yourself up for success by knowing — and preparing for — what lies ahead.



The goal of the keto diet (which encourages eating high-fat, moderate protein and is very low-carb) is for your body to enter ketosis, or a state where it burns fat for fuel, rather than carbs, the normal source of energy. Expect to be in ketosis 24–48 hours after starting the diet, depending on your carb intake, says Scott Keatley, RDN, of Keatley Medical Nutrition Therapy in New York City.

Some people have the wrong impression about keto, assuming it’s a diet where you just avoid grains and sugar. In reality, you also have to forgo legumes, fruit, starchy vegetables and most dairy in order to hit those super low-carb targets. Considering it’s so easy to eclipse the 20–50 gram daily carb limit (for instance 1 cup of blueberries has more than 20 grams), you have to make sure you’re tracking your carbs very carefully. That means things like counting every baby carrot every step of the way.



For all the stories you may hear about people feeling better than ever on keto, you may not expect what happens to so many in the beginning: the keto flu. “The keto flu is less of an illness and more of a feeling of lethargy,” says Keatley. Your body prefers to source its energy from carbohydrates, he notes. When it makes the transition to being a fat-burner, “your body is unable to supply the energy you need as quickly,” he adds. Expect this not-great feeling to stick around for a week or less until you adjust. Keatley advises adjusting your diet gradually (decrease carb intake while upping fat) to make the transition smoother.



Remember how we said your body loves to run on carbs? Keto may have a negative effect on your gym sessions if your muscles don’t get the fuel they need. “Some research has had mixed results when it comes to endurance and strength on the keto diet, so it’s hard to know for sure if your workout will be impaired or improved on keto,” says Abbey Sharp, registered dietitian and author of “The Mindful Glow Cookbook.” “My experience tells me most people thrive exercising with some quality energy from carbs, so until your body is a pro at running on fats, it will likely be a tricky transition,” she says. One study in the journal Metabolism concluded that after 12 weeks of keto adaptation, endurance athletes lost more weight and body fat compared to a high-carb group without impacting their performance. However, the study also found the athletes said their energy dropped for the first 7–10 days, and then their performance suffered for 4–6 weeks. It concludes that if you’re an athlete going keto, you should time it right and avoid starting the diet 4–6 weeks before an event.



Most Americans don’t get enough fiber to start with — and that’s before cutting out fiber-rich foods like beans, whole grains, fruits and veggies, as is necessary on keto. During the diet, where the focus is on meat and fats, which don’t contain fiber, it’s easy to miss out on the digestion-friendly nutrient. “Cutting down on these sources of fiber can lead to difficulty ‘going,’” says Keatley. No matter your diet, your goal should be about 25 and 38 grams of fiber daily for women and men, respectively. If you do get stopped up with constipation, Sharp recommends increasing your consumption of high-fiber vegetables (like avocado, broccoli and greens), drinking more water and upping your activity level.



Or anyone else, for that matter …

While someone may say they’ve never felt better and can think clearly, you may find the exact opposite. “Keto fans often suggest they feel and think better on keto, while others tell me they couldn’t get anything accomplished in the day because they felt in a fog, even after months of trying the diet,” says Sharp. Check in with yourself often and adjust where necessary. Consider working with a registered dietitian, who can help you plan a diet to feel your best, before embarking on keto. It’s also worth mentioning that what you eat is supposed to make you feel great; if keto makes every day a slog to get through and you’re miserable, it may not be right for you. (And, hey, that’s OK.)



Keep a water bottle by your side and sip often throughout the day. On keto, kidneys excrete more electrolytes and water, so it’s easy to get dehydrated, says Sharp. For the same reason, make sure to salt your food to get the sodium you need.



When you hear the word diet, you assume you’re going to go around hungry. And while keto is restrictive, it is made up of mostly fat. “Fat is very satiating, so many people are surprised at how full they are,” says Sharp. Many people find it tough to eat enough fat throughout the day, she adds, so it might take some work to get your daily intake perfect. Fair warning.

About the Author

Jessica Migala
Jessica Migala

Jessica Migala is a health and fitness freelancer based in the Chicago suburbs. She spends her days writing with her beagle mix by her side and her free time with her two young sons. Jessica also writes for O, The Oprah magazine, Woman’s Day, Real Simple and others. Find her at jessicamigala.com.


4 responses to “7 Things You Should Expect When Going Keto”

  1. Avatar Musclefood says:

    Sodium intake should not be anywhere close to an issue with the amount of meats and fats consumed. One will however, need to supplement other aspects of a diet that would be deficient. Most experienced Ketoers use potassium as a salt substitute. Daily multivitamins are always suggested as well.

  2. Avatar Bart says:

    Yet another bogus hit piece on ketogenic diet from MyFitnessPal. Amazing. Most of this is complete farce. First of all, ketosis need not be a goal. Give up sugar and grain, that’s 90% if the battle, and exactly why these paid shills write articles that somehow insist you go off on a fringe diet as a result. Nothing could be further from the truth. Prove it to yourself. Give up all sugar and flour and limit fructose for two weeks. Also, eliminate seed oils (so called “vegetable” oils) and use butter, tallow, coconut oil, avocoda or olive oil instead. Then see how you feel.

  3. Avatar sam says:

    Guys, really?

    In every article i see that doesn’t praise keto
    as the perfect diet that will MAGICALLY MELT ALL YOUR FAT AWAY NO
    keto fanatics claiming “oh, another keto hater. Well guess what, this
    diet works for me and should work for everyone on planet earth”
    Nowhere in this article did the writer claim that the diet is bad for
    everyone – she even agreed that it can work for many. She just
    introduced some REAL side effects of the keto diet, based on REAL
    But the fact is, just because it worked miraculously
    for you doesn’t mean it’s THE perfect diet. I am doing perfectly fine
    on a high carb dieting, weighing 180 at 15% bodyfat (just finished a
    bulk cycle – getting ready to cut again – using high carb dieting) but
    maybe it doesn’t work for everyone and I accept that. But stop acting
    like any nutritionist who doesn’t praise keto and says it’s ideal for
    everyone is immediately a keto hater who wants everyone to get fat on
    sugary foods…

  4. Avatar Eleda says:

    It’s a disservice to women that no one discusses the fact that the ketogenic diet can interfere with menstrual cycles. Prior to starting the diet I read several articles on ‘what to expect’ and the ‘downsides’ of keto. Not a single one mentioned this incredibly important information.

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