The intro period of a carb-free diet can be a real pain in the butt — and the head, literally. If you're like many low-carb newbies, you're probably experiencing a few uncomfortable symptoms, including a low-carb headache, as your body adjusts to your new diet. Once you've passed the introductory phase, the "keto headache" should subside.
The Dirt on Ditching Carbs
Stop eating carbs, lose weight, have more energy, sleep better, feel happier! That's what the low-carb hype promises. A lot of it may come true, especially if you were eating a lot of processed junk before you started on this journey. But getting there can be tough. You've basically taken away your body's primary source of energy — something that was at its immediate disposal — and asked it to flip a switch and burn fat for fuel. Right now, your body is like, "What the...?"
You might feel like you're going through w_ithdrawal,_ and that wouldn't be far from the truth. According to a study published in February 2015 in the journal Plos One, highly processed, carbohydrate-rich foods, such as sweets and chips, may have characteristics similar to drugs of abuse and are frequently associated with addictive-like eating behaviors.
Low-Carb Diet Side Effects
While carbs aren't hard drugs, kicking them can cause some pretty uncomfortable side effects that can be disruptive to your everyday life during the breaking-in period. While this is not a condition recognized by conventional medicine, according to Harvard Medical School lecturer and clinical assistant professor at Tufts School of Medicine Dr. Marcelo Campos, popular culture has termed this cluster of symptoms the "keto flu." Headache is a common symptom, and you may also experience:
- Brain fog
- Constipation or diarrhea
- Bad breath
- Muscle weakness
- Muscle cramps
- Skin rash
How long these side effects last depends on the individual, his sensitivity to carbs, how many carbs he used to consume, and the types of carbs he was eating before he started the diet. People generally report symptoms lasting through the first week, but they could stick around for as long as one month.
How Low Can You Go?
The bigger the change from your old diet to your new diet, the worse your symptoms may be. If you've gone from consuming somewhere around the carbohydrate dietary reference intake (DRI) of around 130 grams (the minimum amount of carbs recommended for adults) , or 45 to 65 percent of your calories (which on a 2,000-calorie diet amounts to 225 to 325 grams), to eating virtually no carbs, you can expect the side effects to be fairly remarkable. Not only is it going to be a very difficult time for you, but it also may not be healthy.
You need some carbs in your diet because carbs from healthy foods provide nutrients your body needs that can't be found in proteins and fats. Namely, you need dietary fiber, the "roughage" that comes from plant cell walls. Your body can't digest fiber, but it doesn't need to digest it to take advantage of fiber's health benefits, which include:
Improved digestion: Fiber adds bulk to stool and helps it pass more easily, decreasing your risk of constipation.
Improved bowel health: A diet rich in fiber can lower your risk of digestive diseases such as hemorrhoids and diverticulitis, according to the Mayo Clinic. Eating enough fiber can also lower your risk of colon cancer.
Lower cholesterol levels: A type of fiber called soluble fiber can help reduce the absorption of cholesterol into your bloodstream. According to Mayo Clinic, consuming 5 to 10 grams of soluble fiber from fiber-rich foods like beans, Brussels sprouts, apples and pears each day can lower your LDL cholesterol — the bad type of cholesterol that increases your risk of heart disease.
And, if you're cutting out carbs for weight loss, you're doing yourself a disservice by not eating any carbs, because fiber aids weight management. According to a review published in the Journal of Nutrition and Metabolism in January 2019, a higher fiber content increases a meal's satiety value and helps control appetite. Because fiber swells in the stomach, it creates gastric distension. This sends signals to the brain that you are full and satisfied, and it delays the release of a hormone called ghrelin that stimulates appetite.
Plant foods are also rich sources of powerful disease-fighting antioxidants. These substances may help protect your cells from free radical damage that increases your risk of heart disease, cancer and other diseases, according to the Mayo Clinic. Healthy complex carbohydrate foods, such as fruits, vegetables and whole grains, are the best sources of these health-boosting compounds.
Fix Your Keto Headache
All of this is to say that you should be eating some carbs, and doing so may help alleviate your headaches. Typically, the maximum amount of carbs allowed on a keto diet is 50 grams, but some keto diet plans call for 20 grams or less each day. Even with a 20-gram allowance, you can fit in several servings of nutritious veggies each day that will help you feel better, control your appetite and improve your overall health.
For example, some raw vegetable options allowed on the Atkins 20 diet that provide 3 grams or fewer carbs per half-cup serving include:
- Alfalfa sprouts
- Spinach radishes
- Button mushrooms
- Bell peppers
And some cooked options:
- Bok choy
- Turnip greens
- Collard greens
- Swiss chard
- Green beans
So, first things first: go make yourself a nice salad. You can even spice it up with a few low-carb options such as red wine vinegar, lemon juice and small amounts of Caesar, blue cheese, ranch or Italian dressings.
Next, have a big glass of water — then drink some more. Ketosis can cause dehydration, which can make your headaches worse. This is especially true if you're exercising and sweating a lot. The Atkins 20 diet recommends drinking eight 8-ounce glasses of water each day, but it doesn't hurt to aim for more than that.
The loss of fluids can lead to imbalances in your body's levels of electrolyte minerals calcium, potassium, magnesium and chloride. This will also make you feel pretty icky and worsen your headaches.
Eating plenty of colorful vegetables will help you replace some of these minerals. You can also eat some nuts and seeds to get extra magnesium and sprinkle a little extra salt on your meal for sodium. Don't go overboard with the salt, though, as that can increase dehydration.
- Plos One: "Which Foods May Be Addictive? The Roles of Processing, Fat Content, and Glycemic Load"
- Harvard Health Publishing: "What Is Keto Flu?"
- Mayo Clinic: "Low-Carb Diet: Can It Help You Lose Weight?"
- Intermountain Healthcare: "Beware the Keto Flu"
- National Academy of Medicine: "Dietary Reference Intakes: Macronutrients"
- Mayo Clinic: "Dietary Fiber: Essential for a Healthy Diet"
- Mayo Clinic: "Cholesterol: Top Foods to Improve Your Numbers"
- Journal of Nutrition and Metabolism: "The Role of Fiber in Energy Balance"
- Mayo Clinic: "Antioxidants"
- StatPearls: "Ketogenic Diet"
- Atkins: "List of Low Carb Foods for Atkins 20, Phase 1"