In short, it can help improve important health markers.
But while the keto diet has many research-backed benefits, it doesn’t work for everyone. Many individuals feel much better on keto while others seem to notice only a few improvements, apart from weight loss — or simply find it too restrictive for their lifestyle.
This guide answers important questions like: How does keto work? Do low-carb diets work for everyone? Who should (and should not do) keto?
Moreover, if you decide to follow the keto diet, here’s how to maximize it for better health and fitness.
This carb reduction forces your body to deplete its stored glycogen (the storage form of glucose) and mobilizes fatty acids, increasing your ketones (*). These include beta-hydroxybutyrate and acetoacetate, which are the two main ketones, and acetone, which is the least abundant (*).
By replacing carbs with fat and teaching your body to rely on its fat stores (through ketosis), individuals experience steadier energy levels.
This is the opposite of depending on carbs for fuel, which tend to cause blood sugar highs and lows — a common occurrence, especially among people with diabetes or pre-diabetes, and who are sensitive to carbohydrates.
In fact, a systematic review and meta-analysis revealed that consuming carbs is linked to higher levels of fatigue and less alertness (*).
Carbs may be low on keto, but it’s important to replace this energy source with fat. Fat should make up most of your calories, as this does not only provide fuel but also support your hormones and other vital bodily functions.
Meanwhile, protein should be moderate, unless you’re following a high-protein approach on keto for athletic and body recomposition purposes.
This low-carb high-fat approach advocates for foods like eggs, meat, poultry, fish and seafood, nuts, seeds, green vegetables, and low-sugar fruits. Make sure to avoid all grains, starchy veggies (like potatoes and carrots), and traditional desserts and pastries.
The benefits of keto, such as weight loss and improved health markers (like blood sugar, HDL cholesterol, and blood pressure) make it appealing to a lot of people needing help with these aspects. However, because everybody is different, keto may not work for some. Below is a list of factors that affect your experience or results with low-carb:
- Personal readiness: Research suggests that health counseling mostly benefits people who have the willingness to change and embrace healthy behaviors (*). In other words, no amount of information can motivate you to try a keto diet (or any other diet for that matter) in the first place if you’re not personally ready for it.
- Food preferences and the keto flu: Giving up carbs can be difficult for a lot of people. Furthermore, you may start off motivated and convinced of the benefits of keto, but intense hunger and sugar cravings kick in within the first few days of keto. You’ll also experience other keto flu symptoms like fatigue and headache (*).
- Current health condition and medication: Although keto helps people with diabetes, it’s still important to consult your healthcare provider and seek medical supervision. This is especially important for those who are taking blood glucose-lowering medications. Your healthcare provider may make some adjustments to your medications to prevent dangerously low blood glucose (since keto lowers blood glucose already) (*).
Individuals who can greatly benefit from the keto diet include those who need help lowering their blood sugar levels and losing weight.
Multiple studies have shown that the keto diet improves glycemic control while contributing to weight loss. For instance, obese diabetic patients achieved a weight loss of 8.66 kg. Researchers have also found that on top of weight loss, their systolic blood pressure was reduced by 4.30 while diastolic blood pressure was reduced by 5.14. This improvement in blood pressure may have resulted from weight loss (*).
Diabetic patients who try the keto diet may also experience relief from symptoms like limb numbness, insomnia, and fatty liver (*).
Also, some people feel bad after eating carbs. They find themselves feeling bloated, tired, and experiencing brain fog. Others find it hard to regulate carbs on a standard Western diet (especially from highly desirable foods like pastries) — and more often than not, a small “treat” would result in a binge. This is why they choose to do keto.
Does keto really work for epilepsy? Yes. In fact, the classic keto diet (high-fat, low-carb, and moderate-protein) has been used in children with epilepsy since the 1920s (*).
On the contrary, some people consider keto diets as restrictive diets for the reason that keto impairs their athletic performance. While research shows that the keto diet (and supplementing with ketones) help endurance athletes, sprint-type or high-intensity aerobic exercise may be compromised on keto (*, *).
That said, if you’re a marathon runner or long-distance cyclist, there’s a higher chance you’ll benefit from keto — compared to someone who regularly does high-intensity workouts that engage fast-twitch muscles (*).
A word of advice: If you want to do keto as an athlete, always keep in mind that keto-adaptation (also called fat-adaptation) takes time. It’s easier to enter ketosis than making your body truly adapt to using ketones as its main fuel source. In addition, keto athletes can follow a targeted keto diet in which they consume carbs around their workouts to sustain their performance (*).
Whether it’s speeding up weight loss, reducing its short-term keto flu side effects, helping your body adapt sooner, avoiding dangerously low blood sugar levels, and feeling your best — here are helpful strategies to implement:
- Get your nutrients from whole foods such as meats, fatty fish, seafood, leafy greens, cruciferous veggies, berries, avocados, nuts, seeds, eggs, and unprocessed cheese. Limit your intake of processed keto items which may contain added sugars and refined vegetable oils.
- Minimize keto flu symptoms by taking an electrolyte drink, staying hydrated, increasing dietary fat, getting proper rest, and cutting back on your workouts until you feel better.
- Once you become keto-adapted, you can incorporate intermittent fasting (IF) to experience greater fat loss or get past a keto diet weight loss stall.
- If you have a medical condition like diabetes, consult your healthcare provider. As mentioned previously, blood glucose medications may need to be adjusted to prevent hypoglycemia (or below-normal blood glucose readings).
Other healthy practices like adequate sleep, stress management, and exercise are all essential for making the keto diet work to your advantage.
Keto can be beneficial for a lot of people; however, you may personally find other diets more appealing due to flexibility or personal food preferences.
One keto diet alternative is the Paleo diet, which eliminates grains and refined sugars, and includes lean meats, nuts and seeds, and fish that are rich in omega-3s. Carbohydrate intake can range from 100 grams to 300 grams per day depending on a person’s goal.
Another option is the Atkins diet which is still considered a low-carb diet. However, unlike keto, the Atkins diet involves gradually increasing carbs and it allows for some grains.
Do keto diets work? They do, for many reasons such as weight loss, blood glucose control, and improvement in other health markers.
But, at the end of the day, you’re the one who knows which diet to follow. Keto or not, the right diet is one that is supported by research, supervised by a knowledgeable and experienced health professional (for people with medical conditions), and one that you can stick to because it suits your lifestyle.
Furthermore, combine good nutrition with lifestyle practices like sleep, exercise, stress reduction, and supplementation as needed. Doing this will help you get healthier and fitter on your diet.