Even a cursory investigation of the ketogenic diet is likely to yield plenty of information about the dreaded “keto flu”--the body’s reaction to reducing or eliminating carbohydrates from the diet. Symptoms include headaches, muscle cramps, mental fogginess, and fatigue as the body resists giving up simple sugars and carbohydrates in favor of using fat stores for fuel.
Fortunately, there’s a critical but sometimes overlooked solution to counteract keto flu: keeping a sharp eye on your electrolytes (sodium, magnesium, and potassium), particularly potassium.
Why is potassium so important to the ketogenic diet? What are the risks and symptoms of potassium deficiency? What are some of the best sources of natural potassium? And what should you know about supplementing with potassium?
We’ve compiled the answers to the top questions about potassium below!
Electrolytes and the Ketogenic Diet
Electrolytes like potassium are critical to the body’s ability to turn fat into energy in all diets and lifestyles. However, in the ketogenic diet, in which the body is required to rely more heavily on stored fat for energy, electrolytes are of the utmost importance.
Not only is potassium a required mineral for ketogenesis (the process of turning fat into energy); it’s also critical for exercise because of its role in metabolizing foods, muscle contraction (including the muscles of the heart!). This important mineral is flushed from the body during exercise and can be easily depleted in the ketogenic diet.
The Food and Nutrition Board of the Institute of Medicine recommends that adult men and women needs approximately 4,700 mg of potassium per day. This might sound like a lot--until you consider the fact that for many people, the body flushes approximately the same amount per day. Since the ketogenic diet often has a diuretic effect on the body, you are likely to flush more electrolytes like potassium from your body than the average person. Increasing your potassium intake by 1,000 mg, either naturally or through supplements, while on a ketogenic diet, will help avoid potassium deficiencies.
Symptoms and Risks of Low Potassium
Because of potassium’s critical role in energy production and exercise, it’s important to pay attention to the symptoms of low potassium and adjust your levels accordingly through natural potassium sources and supplements.
Symptoms to be on the lookout for include the following:
- Irregular heartbeat, or arrhythmia
- Irritability or depression
- Muscle weakness and cramps
- Heart palpitations
- High blood pressure
In very severe cases, respiratory distress, heart failure, stroke, or osteoporosis can occur. Making a dedicated effort to keep your electrolyte levels in a healthy range will keep these symptoms from occurring. If you notice any of these symptoms, A simple blood or urine test (some of which can be done at home) can give you a good idea of your potassium levels.
Good Sources of Natural Potassium
As anyone who adheres to the ketogenic diet knows, many of the foods that contain high levels of potassium are also carbohydrates (e.g., bananas and orange juice)--another reason it can be difficult to maintain healthy potassium levels.
However, by paying attention to foods with high potassium levels and incorporating them into your diet, you can keep your electrolyte levels in the healthy range. The following are some of the best sources of potassium that are compatible with the ketogenic diet:
- Avocado: (1,000 mg per piece)
- Salmon (800 mg per filet)
- Broccoli (468 mg)
- Nuts (100-300 mg per 30 g, depending on type of nut)
- Dark leafy greens like kale or spinach (160 mg per cup raw, 840 mg per cup cooked)
- Tuna (275 mg)
- Mushrooms (100-200 mg per cup)
- Grapefruit (166 mg)
Supplementing with Potassium
Getting enough potassium naturally can be difficult even without the unique metabolic requirements of the ketogenic diet. That’s why many people on the keto diet decide to supplement with potassium to aid with energy production and to avoid the symptoms of keto flu.
If you decide to supplement with potassium, there are a few things you should be aware of:
- The Food Board of the Institute of Medicine hasn’t established an “upper limit” when it comes to potassium intake, but it is possible to overdose when taking potassium supplements, resulting in a condition called hyperkalemia. This condition can, in extreme cases, be fatal--which is why the FDA has restricted supplements from containing more than 99 mg of potassium. However, that means you’d have to take more than 45 of these pills just to reach your daily nutritional requirements of potassium! For healthy individuals, there’s little need to worry about overdosing from potassium from natural sources, and for people on the ketogenic diet that struggle to reach the daily nutritional requirements for potassium naturally, potassium supplements can be a tremendous help.
- If your kidneys are impaired (in other words, aren’t able to flush out excess potassium properly), it’s especially important to talk to a doctor before supplementing.
- The amount of potassium you choose to supplement with can (and should!) vary depending on your diet and exercise routine. If you are keto dieting, you may choose to take, for example 500 mg of additional potassium per day to help ensure you meet your minimal nutritional requirements for this important nutrient. On days that you include a vigorous workout in your routine, you may choose to increase that supplement to 1000 mg. Always consult your doctor to determine the right amount for your lifestyle and activity levels.
- Some over-the-counter pain relievers, and some antihypertensive drugs can have a big impact on the amount of potassium you retain. Talk to your doctor before supplementing if you are on medication that may improve your potassium retention.
- It’s a good idea to supplement with magnesium in addition to potassium, since this mineral will help with potassium absorption, or your body’s ability to use that potassium.
- Taking potassium supplements in large amounts can irritate your GI tract, resulting in an upset stomach or gas. To counteract this side effect, break scored supplements in two, and take potassium supplements with water.