The ketogenic diet (KD), characterized by its high-fat, very low-carbohydrate composition, has garnered significant attention for its potential benefits in weight loss, managing certain medical conditions, and improving metabolic markers. Nuts, including walnuts, can be a valuable addition to a ketogenic diet due to their healthy fats, fiber, and nutrient content. This article delves into the role of walnuts in a ketogenic diet, exploring their nutritional profile, potential benefits, drawbacks, and important considerations for those following this dietary approach.
Understanding the Ketogenic Diet
The ketogenic diet is a low-carbohydrate diet (LCD) with a moderate amount of protein restriction designed to induce ketosis without restricting fat intake. The concept of KD was initially developed in 1921 by Dr. Russel Wilder for the management of refractory seizures in pediatric patients. It involves drastically reducing carbohydrate intake, typically to less than 50 grams per day, and increasing fat consumption to as much as 70-80% of daily calories. This restriction forces the body to switch its primary fuel source from glucose to ketones, which are produced from the breakdown of fats in the liver. This metabolic state, known as ketosis, is the cornerstone of the ketogenic diet.
How Ketosis Works
Following CHO deprivation and depletion of glycogen stores, the body undergoes metabolic changes to provide an energy source for the body through gluconeogenesis and ketogenesis. Gluconeogenesis can be sustained for three days with adherence to an LCD, and subsequently, additional energy sources are necessary to meet the metabolic requirements of the body and brain. In ketosis, the body uses fat for fuel, instead of sugar (glucose). When these stores are full, they are converted into fat. In this state, your body breaks down fats into molecules called ketones. Ketones serve as an alternative fuel source.
Different Types of Keto Diets
There are several different styles of keto diets.
- Standard Ketogenic Diet (SKD). This is the original and best-studied of the different diet strategies. All foods must be weighed on a scale to achieve a relative weight distribution of 4 grams of fat for every 1 gram of combined protein and carb eaten throughout the day. In other words, you will likely need to avoid all carb-rich foods (like pasta, potatoes, fruit, etc.). A typical meal might look like half an avocado with a small piece of salmon cooked in a lot of olive oil with a side salad. It will all be topped with a cream sauce made with heavy cream and cheese.
- Targeted Ketogenic Diet (TKD). This diet generally still requires a scale for weighing food. It's defined by a ratio closer to 3 grams of fat for every 1 gram of combined protein and carb (generally with a focus on more protein than carbs). In other words, you'll still avoid most carb-rich foods except for maybe one or two servings per day.
- Simplified Keto. This diet is the more user-friendly keto diet and likely the most popular. These diets generally avoid all starchy foods (pasta, rice, potatoes, bread, corn, peas, beans and legumes). Desserts and any other high-carb foods are also not part of the diet.
Nutritional Profile of Walnuts
Walnuts are versatile, high-fat, low-carb nuts used in various dishes. They offer a wealth of nutrients that can complement a ketogenic diet. A one-ounce (28 grams) serving of walnuts contains approximately:
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- Calories: 185
- Protein: 4 grams
- Fat: 18 grams
- Total Carbohydrates: 4 grams
- Fiber: 2 grams
- Net Carbohydrates: 2 grams
In addition to these macronutrients, walnuts also contain calcium, iron, magnesium, selenium, zinc, and copper. They are particularly rich in alpha-linolenic acid (ALA), an omega-3 fatty acid, and antioxidants, making them a valuable addition to a balanced diet.
Benefits of Walnuts on a Ketogenic Diet
1. Keto-Friendly Nutritional Profile
Walnuts align well with the macronutrient ratios of a ketogenic diet. Their high-fat content helps meet the dietary fat requirements, while their low net carb content ensures that they won't disrupt ketosis.
2. Source of Healthy Fats
Walnuts are rich in polyunsaturated fats, including ALA, an essential omega-3 fatty acid. These fats are beneficial for heart health and overall well-being. Incorporating walnuts into a keto diet can help ensure an adequate intake of these essential fats.
3. Rich in Antioxidants
Walnuts are a great source of alpha-linolenic acid (ALA), an omega-3 fatty acid that is important for reducing inflammation. Walnuts also contain antioxidants and anti-inflammatory polyphenols (compounds) that may improve brain function and slow mental decline that occurs with aging. The antioxidants in walnuts help combat oxidative stress and inflammation in the body, which can be particularly important during the metabolic changes associated with ketosis.
4. Improved Gut Health
Bacteria and microbes in your intestines and gut are also essential to your health. Research shows walnuts can improve gut health. Microbes in your gut take compounds found in walnuts and produce urolithin compounds. These urolithins may help lower risk for certain cancers. Walnuts have been shown to promote a healthy gut microbiome, which is crucial for digestion, nutrient absorption, and overall health.
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5. Versatility in Keto Recipes
Walnuts can be easily incorporated into various keto-friendly recipes. They can be added to salads, keto-friendly desserts like fudge or brownies, or enjoyed as a snack on their own.
Potential Drawbacks and Considerations
1. Calorie Density
While walnuts offer numerous health benefits, they are also calorie-dense. It's important to consume them in moderation to avoid exceeding daily calorie goals, especially when following a ketogenic diet for weight loss. Recent research suggests that the way fat is stored in walnuts prevents your body from holding onto all the calories.
2. Allergenicity
Walnuts are a common allergen. Individuals with tree nut allergies should avoid walnuts and products containing them.
3. Oxalate Content
Walnuts contain oxalates, which can contribute to kidney stone formation in susceptible individuals. Those with a history of kidney stones should consume walnuts in moderation and stay well-hydrated.
4. Potential for Overconsumption
Low carb nuts are infamous for being easy to snack on, and the more you eat them, the more calories you load up. That’s why serving size matters. Make sure that you eat the right portion sizes. Due to their palatability, it's easy to overeat walnuts, potentially hindering weight loss efforts. Practicing mindful eating and portion control is essential.
Read also: Hill's Science Diet: Pros, cons, and expert analysis.
Incorporating Walnuts into a Ketogenic Diet
1. Portion Control
Stick to a one-ounce serving (approximately 1/4 cup) of walnuts per day to manage calorie and carbohydrate intake.
2. Snacking
Enjoy a small serving of raw, unsalted walnuts as a snack to curb hunger and provide a healthy dose of fats and nutrients. To maximize the health benefits, look for raw, unsalted walnuts.
3. Recipe Integration
Add chopped walnuts to keto-friendly salads, desserts, or use them as a topping for meat and vegetable dishes. You can add walnuts to keto-friendly desserts like fudge or brownies.
4. Walnut Flour
Use walnut flour as a low-carb alternative to wheat flour in baking recipes.
General Benefits and Drawbacks of the Ketogenic Diet
While incorporating walnuts into a ketogenic diet can offer several benefits, it's important to consider the broader implications of following a ketogenic diet.
Potential Benefits of KD
- Weight Loss: KD has been shown to effectively lead to weight loss. Research suggests that the keto diet helps people cut calories because the diet doesn't include many foods that people are likely to overeat.
- Reduction in Hyperinsulinemia: KD can help reduce hyperinsulinemia.
- Improvement in Insulin Sensitivity: KD can lead to improved insulin sensitivity.
- Management of PCOS: KD has been postulated to positively impact women diagnosed with polycystic ovarian syndrome (PCOS).
- Management of Diabetes: As mentioned previously with regard to patients with PCOS, the same benefits of following a VLCKD apply to patients with diabetes as well.
- Treatment for Epilepsy: The keto diet was first used as a treatment for pediatric drug-resistant epilepsy to reduce seizures in the 1920s. when medications alone aren't enough.
- Brain Health: The keto diet can show positive results for helping the brain. It's been used for years to treat epilepsy. Researchers are looking to see if the keto diet can help treat age-related brain decline and potentially Alzheimer's disease. There are many different theories as to why the keto diet may be beneficial for brain health. These include the direct benefit from the presence of ketone bodies, especially one called beta hydroxybutyrate.
Potential Drawbacks of KD
- Nutrient Deficiencies: The keto diet is very low in carbs which means you can't eat many fruits and vegetables. Because of the stringent food restrictions, many find the keto diet hard to stick to. “The ketogenic diet can be effective for weight loss when used in a short time period followed by the adoption of healthier eating habits.
- Possible Negative Effects on Heart Health: There are mixed results in studies that examine the specific effects of the keto diet on heart health. This is likely because much of it depends on individual food choices. The high-fat nature of the diet could also have negative impacts on heart health. The American Heart Association recommends limiting saturated fat intake to less than 6%.
- Constipation and Other Gastrointestinal (GI) Troubles: Constipation is likely the greatest long-term complication of the keto diet because of a low fiber intake. Fiber is a form of carb that is digested not by our human cells, but by the microbes in our gut.
- Keto Flu: Also, when people start the keto diet, they go through the keto flu. Keto flu symptoms appear a few days after starting the diet. This eventually goes away once your body adjusts to your eating changes. Common short-term side effects resulting from the initiation of KD have been referred to as “keto flu,” which encompasses symptoms including fatigue, headache, dizziness, nausea, vomiting, constipation, and low exercise tolerance. Symptoms typically resolve after a few days to weeks as the body adjusts to the low CHO, ketogenic state.
- Kidney Problems: The kidneys help metabolize protein, and McManus says 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,” says Dr.
- Fuzzy Thinking and Mood Swings: The brain works best when the energy source is sugar from healthy carbohydrates to function.
- Drop in Blood Pressure and Blood Sugar: 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.
- Non-Sustainability: Long-term adherence to KD is a major challenge and that is why this type of diet is considered non-sustainable.
Other Considerations
- Long-Term Compliance: While the benefits of following KD have been extensively reported, long-term compliance with KD is a limiting factor.
- Underlying Conditions: The diet is limited and/or contraindicated in patients with liver failure, pancreatitis, inborn disorders of fat metabolism, primary carnitine deficiency, carnitine palmitoyltransferase deficiency, carnitine translocase deficiency, porphyria, and pyruvate kinase deficiency.
Keto-Friendly Nuts and Seeds
Many nuts and seeds are low in net carbs (total carbs minus fiber) and high in healthy fats, making them a perfect fit. Here are some of the best nuts and seeds to fit your keto lifestyle:
- Pecans
- Brazil nuts
- Chia seeds
- Macadamia nuts
- Flax seeds
- Walnuts
- Hemp seeds
- Hazelnuts
- Peanuts
- Sesame seeds
- Pine nuts
- Sunflower seeds
- Almonds