The ketogenic (keto) diet has gained considerable attention as a weight-loss strategy and potential therapy for various health conditions. This article explores the principles behind the keto diet, its potential benefits, and the risks associated with it.
What is Ketosis?
Ketosis is a metabolic state where the body primarily uses fat for fuel instead of glucose. Normally, the body relies on glucose, which is derived from carbohydrates, as its main energy source. When carbohydrate intake is significantly reduced, the body's glucose stores deplete. In response, the body begins to break down fat into molecules called ketones, which then serve as the primary fuel source for the body and brain. The liver produces a small amount of ketones on its own. But when your glucose level decreases, your insulin level decreases. This causes your liver to ramp up the production of ketones to ensure it can provide enough energy for your brain. Therefore, your blood has high levels of ketones during ketosis.
Understanding the Ketogenic Diet
The ketogenic diet is a high-fat, moderate-protein, and very low-carbohydrate diet. The standard keto diet typically consists of 70-80% fat, 10-20% protein, and 5-10% carbohydrates. This macronutrient distribution forces the body to shift its metabolic focus from glucose to fat, inducing ketosis. Many nutrient-rich foods contain high amounts of carbohydrates, including whole grains, fruits, and vegetables. Carbs from all sources are restricted on the keto diet.
To achieve and maintain ketosis, carbohydrate intake must be restricted to under 50 grams per day. To put this in perspective, that's about three slices of bread, two bananas or 1 cup of pasta. The types of foods that provide fat for the keto diet include: Meats and fish, Eggs, Nuts and seeds, Butter and cream, Cheese, Oils such as olive oil and canola oil.
It typically takes two to four days to enter ketosis if you eat between 20 and 50 grams of carbohydrates each day. However, the time it takes to enter this state varies based on several factors. It may take you a week or longer to get into ketosis. Factors that may influence how long it takes you to achieve this state include your: Age, Carbohydrate, fat and protein intake, Physical activity level, Metabolism, Sleep health, Stress level. If you eat a high-carb diet before starting a keto diet, it may take you longer to reach ketosis than someone who consumes a low-carb diet. That’s because your body needs to exhaust its glucose stores first. You may be able to get into ketosis faster with intermittent fasting. The most common method of intermittent fasting involves eating all of your food within eight hours. Then, you fast for the remaining 16 hours of a 24-hour period.
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Potential Benefits of Ketosis
Research suggests that ketosis may offer several health benefits, including:
Weight Loss
One of the most significant benefits of ketosis is its potential to promote weight loss. By reducing carbohydrate intake, the keto diet can help individuals feel less hungry, leading to reduced food consumption. It can help you lose belly fat (visceral fat) while maintaining a lean mass. Studies have found that individuals on a keto diet report less hunger and desire to eat.
Management of Type 2 Diabetes
The keto diet can be a valuable tool for managing blood sugar levels in individuals with type 2 diabetes. Low carb diets have been a mainstay of diabetes management, and they were recommended well before injectable insulin became available. One 2019 study found that a keto diet reversed type 2 diabetes in some participants, and after a 2-year follow-up, many participants had improvements in their diabetes blood markers. Among participants, there was a diabetes remission rate of 17.6%.
Neurological Conditions
Healthcare providers often put children with epilepsy on the keto diet to reduce or even prevent seizures by altering the “excitability” part of their brain. Research has shown the keto diet may help improve neurological conditions such as Alzheimer’s disease, autism and brain cancers such as glioblastoma.
Cardiovascular Health
The keto diet may lower your risk of developing cardiovascular disease by lowering your blood pressure, improving your HDL (“good”) cholesterol levels and lowering your triglycerides. The keto diet may reduce your risk of developing metabolic syndrome, which is associated with your risk of heart disease.
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Increased Focus and Energy
Ketosis has also been shown to increase your focus and energy. The keto diet delivers your body’s energy needs in a way that reduces inflammation. Research suggests your brain works more efficiently on ketones than on glucose.
Potential Risks and Side Effects
While the keto diet offers potential benefits, it's important to be aware of the potential risks and side effects:
"Keto Flu"
One of the initial side effects of starting a keto diet is the "keto flu," which can manifest as upset stomach, headache, and fatigue. Symptoms typically resolve after a few days to weeks as the body adjusts to the low CHO, ketogenic state.
Nutrient Deficiencies
Because the keto diet limits carbs to just 50 g, it doesn’t leave room to include many fruits or vegetables. These are your body’s primary source of essential vitamins and minerals, all of which play a role in keeping your cells healthy. Strict diets like keto could also cause social isolation or disordered eating.
Digestive Issues
Staying low carb means you won’t be eating many beans, lentils, or whole grains, which are all good sources of fiber. This can lead to constipation and slow digestion. Consuming so much fat can also be tough on your digestive system. Many people who try keto experience gastrointestinal (GI) issues like diarrhea, cramping, bloating, and stomach upset.
Read also: The Keto-Brain Fog Link
Heart Health Concerns
If you’re eating a keto diet that’s high in sources of saturated fat - like meat, cheese, and butter - you’re at risk of harming your heart health. Saturated fat is known to increase levels of LDL (bad) cholesterol, which can clog your arteries. This is associated with heart and cardiovascular disease.
Sustainability and Long-Term Effects
Sticking to a keto diet can be tricky, and it’s not easy to do long term. There’s also no long-term data on its safety, so it’s not something you’d want to do without the supervision of a healthcare professional. It is ultimately not realistic or sustainable. Following a keto diet requires a lot of meal planning and food preparation, and this can be incredibly challenging for people with busy jobs and families. It’s also hard to find keto-friendly options at restaurants and social gatherings, so some people find it negatively affects their social life.
Kidney Problems
The kidneys help metabolize protein, and the keto diet may overload them. The keto diet may not be appropriate for everyone, specifically people with kidney disease. Although more research is needed in that area, there is some suggestion that it can make kidney disease worse over time.
Other Side Effects
The keto diet can cause your blood pressure to drop in the short term due to a reduction in blood volume and changes in your fluid balance. Symptoms of low blood pressure include dizziness, lightheadedness or fainting, especially when standing up quickly. Following a keto diet can also cause your blood sugar to drop, which can be dangerous for people living with diabetes. Common symptoms of low blood sugar include weakness or shaking, sweating, a fast heartbeat and dizziness. Some people also experience dehydration on the keto diet because they’re eliminating glycogen, which holds water, from the bloodstream.
Considerations and Recommendations
Before starting a keto diet, it's crucial to consult with a healthcare professional or registered dietitian, especially if you have any underlying health conditions. They can assess the potential risks and benefits based on your individual needs and health status. The high fat nature of a keto diet might help stabilize blood sugar and support weight loss, but there are also some significant risks to be aware of.
For long-term weight loss, consider making small changes based on your health goals. Just because you were super fit between the ages of 36 and 38 may not extend your healthy life. But if you make small changes consistently every day from ages 36 to 66, that probably will have a big impact. No one diet fits all, and what works for one person may not work for another.
If you find that a lower carb style of eating feels good for your body, trying a more relaxed approach - like a low carb Mediterranean style diet - might be a simpler, more sustainable choice.
The priority should be to reduce simple carbohydrates and include more complex carbohydrates. Complex carbohydrates are high in nutrients and fiber that increase fullness, which can help with weight control. The keto diet is quite restrictive and hard to sustain long-term, making it not the best choice for lifelong weight management. The best diet for weight management is one that can be maintained long-term. Don't restrict carbohydrates - rather, reduce them by choosing more complex carbs. This approach may be more sustainable.
The Keto Diet and Cancer
While the research on keto as part of cancer treatment is new - and highly controversial - some small studies have shown possible benefits. The idea behind this is related to something called the Warburg effect. This claims that there are metabolic changes in cancer cells that mean they primarily use glucose (carbs) for energy, even when oxygen is available. Theoretically, a keto diet that cuts down on carbs and forces the body to rely on fat for fuel might “starve” cancer cells. This could potentially weaken cancer cells, making them more susceptible to chemotherapy and radiation, while protecting normal cells. One small 2023 study found a better overall survival rate in participants who continued the keto diet for longer, but experts note that this research is still in its early stages.