Feeling awful on the ketogenic (keto) diet is a common experience, often referred to as the "keto flu". These temporary, flu-like symptoms occur as your body transitions from burning carbohydrates (glucose) for fuel to burning stored fat (ketones).
Your body's response to entering ketosis can often mimic symptoms of the flu, thus the name “keto flu.” Essentially, you're feeling the symptoms of withdrawal from carbs. Your body burns carbohydrates (glucose) for energy by default so switching to a fat-burning process confuses your body.
Your first week delivers the most dramatic scale changes, but here's the reality check—most of this initial loss is water weight, not fat. This is also widely regarded as the hardest week of your keto journey. When you slash carbs, your body depletes glycogen stores in muscles and liver.
Increased risk of heart disease and diabetes. Followers of the keto diet are encouraged to eat quality proteins, non-starchy vegetables, and fruits, and to go heavy on fats. Placing a high emphasis on fat consumption could increase your risk of developing heart disease and diabetes.
One of the signs of ketosis may include “keto flu,” which includes symptoms such as upset stomach, headache and fatigue. Other symptoms of ketosis may include: Bad breath (“keto” breath). Constipation.
As your body is adapting to a ketogenic diet like Atkins20® or Atkins40® *, a number of changes may occur. These changes are often referred to as the “keto flu.” While these changes aren't dangerous, and usually subside after a week or two, they can be uncomfortable and inconvenient.
Bananas are a great food while you're sick. Keto dieters will also come to love the many benefits of avocados—another food that's great for nourishing a sick body. Foods high in magnesium will also help your body feel better as it recovers. Eat whole foods and avoid falling into “dirty keto” while you're sick.
Cardiologists generally view the ketogenic diet with caution, noting potential short-term benefits like weight loss and improved blood sugar, but highlighting significant long-term risks, including elevated "bad" LDL cholesterol, potential nutrient deficiencies, and a possible increased risk for heart events like heart attacks, strokes, and angina, making it unsustainable and potentially unsafe for many heart patients compared to more balanced, whole-food approaches.
The worst carbs for belly fat are refined carbohydrates and added sugars, found in sugary drinks, white bread, pastries, and processed snacks, because they spike blood sugar and insulin, leading to increased fat storage, especially around the abdomen. While no single carb is solely responsible, these quickly digested, low-fiber options promote inflammation and insulin resistance, contributing to visceral (belly) fat.
Having kidney disease or type 1 diabetes may also make the keto diet dangerous for you. In sum, if you're on keto and notice that your health condition is not improving (or is getting worse), you'd be wise to stop and ask your primary care doctor what eating plan best suits your personal health.
Without adequate electrolyte replacement, you may experience symptoms beyond simple thirst, including muscle cramps, fatigue, and ketosis headaches. The metabolic process of breaking down fat requires significant water intake to process and eliminate waste products effectively.
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Gulotta recommends staying on keto for six months max before reintroducing more carbs to your diet. And Scott Keatley, RDN, of Keatley Medical Nutrition Therapy in New York City, agrees: “The science hasn't gotten to the point where I would be comfortable recommending it as a forever diet,” he says.
You're often low on energy and feel nauseous. Your doctor isn't happy with your latest blood work results either, as the keto diet can increase cholesterol and lipid levels. You and keto just might not be a match.
Metabolites of both serotonin and dopamine had significantly reduced after following the ketogenic diet, demonstrating that these neurotransmitters were being utilised more efficiently in the brain. There have also been some case studies that encourage further research into this field.
Your state of mind can get wonky when you sharply cut healthy carbs that send sugar to the brain. You might feel grouchy. One study found people who followed low-carb diets over time had less serotonin in their brains than those who were on low-fat diets.
The 3-3-3 rule for weight loss is a simple, habit-based method focusing on three key areas: 3 balanced meals a day, 3 bottles (or ~1.5L) of water by 3 PM, and 3 hours of physical activity per week, aiming for consistency over complex diets. It simplifies fat loss by establishing rhythm through consistent eating, adequate hydration to support metabolism, and regular movement, promoting sustainable health without intense calorie counting or restrictive rules, says Five Diamond Fitness and Wellness, Joon Medical Wellness & Aesthetics, and EatingWell.
The number one carb to avoid is added sugar, especially in sugary drinks like soda, sweet tea, and fruit juice, followed closely by refined grains (white bread, white rice, sugary cereals) and highly processed snacks (cookies, cakes, chips) because they offer little nutritional value, cause rapid blood sugar spikes, and contribute to health issues, making them "empty calories".
Strict diets like keto could also cause social isolation or disordered eating. Keto is not safe for those with any conditions involving their pancreas, liver, thyroid or gallbladder.
Ketogenic diets appear to lower blood levels of triglycerides but raise levels of artery-clogging LDL cholesterol.
The rate of weight loss on the keto diet without exercise ranges from 1-2 pounds per week. Therefore, if you want to lose significant weight, reaching your goals may take a few months. Exercise is essential to any weight loss plan, as it helps burn calories, build muscle, and improve overall health.
But with a few simple ingredient swaps, you can satisfy a sweet tooth on this extremely high-fat, low-carb diet. For instance, you can replace white flour with low-carb almond meal or coconut flour. Likewise, you can trade white sugar for sweeteners such as monk fruit extract, stevia, and erythritol to cut carbs.
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If you do not eat enough fat on keto, your body will go into survival mode. This will have an incredibly negative effect on your wellbeing, as you will feel more hungry, causing your body to prioritize storing fat.