The ketogenic diet (or keto diet, for short) is a low-carb, high-fat diet that offers many health benefits.
In fact, many studies show that this type of diet can help you lose weight and improve your health [ PubMed1 ].
The ketogenic diets may even be beneficial in other situations such as diabetes [ PubMed2 ], cancer [ PubMed3 ], epilepsy [ PubMed4 ] and Alzheimer’s disease [ PubMed5 ].
A Mini “Keto” Guide for You. We have prepared a detailed guide for you, with an example of a ketogenic weekly menu , a list of foods to avoid and one with “keto friendly” foods . Enjoy the reading
What is the ketogenic diet?
Interview with Dr. Mikiko Watanabe , endocrinologist and researcher at Sapienza in Rome.
The ketogenic diet is a diet that drastically reduces the intake of carbohydrates and replaces them with fats (yes you got it, fats! .. but keep reading and you will understand what happens).
This carbohydrate deprivation puts your body into a metabolic state called ketosis . When this happens, your body becomes incredibly efficient at burning fat for energy.
Ketogenic diets can cause significant reductions in blood sugar and insulin levels.
The Different Types of Ketogenic Diets
There are several versions of the ketogenic diet [ PubMed6 ], including:
- Classic Ketogenic Diet : This is a low-carb, moderate-protein, and high-fat diet. Typically it contains 70% fat , the 20% protein and only 10% of carboidrat i .
- Cyclical Ketogenic Diet : This diet involves periods of higher carbohydrate replenishment, such as 5 ketogenic days followed by 2 high carbohydrate days.
- Targeted Ketogenic Diet : This diet allows you to add carbs during workouts.
- High Protein Ketogenic Diet : This is similar to a classic ketogenic diet, but includes more protein. The ratio is often 60% fat , 35% protein and 5% carbohydrate .
However, only classic, high-protein ketogenic diets have been extensively studied. Cyclical or targeted ketogenic diets are more advanced methods that should be followed exclusively by consulting nutritionists experienced in ketogenic diets, they are also developed for bodybuilders or athletes.
The information in this article primarily applies to the standard ketogenic diet, although many of the same principles apply to the other versions as well.
There are several versions of the keto diet. The classic keto diet is the most sought after and most recommended.
What is ketosis?
Ketosis is a metabolic state in which your body uses fat for fuel instead of carbohydrates.
It occurs when you significantly reduce your consumption of carbohydrates, limiting your body’s supply of glucose (sugar), which is the main source of energy for cells.
Following a ketogenic diet [ PubMed7 ] is the most effective way to enter ketosis. In general, this involves limiting carbohydrate consumption to around 20-50 grams per day and filling in fats, such as meat, fish, eggs, nuts, and healthy oils.
It is also important to moderate your protein intake . This is because proteins can be converted into glucose when consumed in large quantities, which could slow the transition to ketosis [ PubMed8 ].
Practicing intermittent fasting could also help you get into ketosis faster. There are many different forms of intermittent fasting, but the most common method is to limit food intake to around 8 hours per day and fast for the remaining 16 hours [ PubMed9 ].
Ketosis is a metabolic state in which your body uses fat for fuel instead of carbohydrates. Changing your diet and practicing intermittent fasting can help you get into ketosis faster.
How to measure the state of ketosis
Ketones are very small molecules that are created in the monster liver from fatty acids. A physiological amount of ketone bodies is always present in our body, but when we run out of carbohydrate reserves the production of ketones increases.
The liver begins to produce large quantities of ketones which, compensating for the absence of sugars, will provide large amounts of energy to the body and brain by drawing from the lipid reserves.
The Signals of your body. Some symptoms will indicate that you have entered ketosis, including increased thirst, dry mouth, frequent urination, and decreased hunger or appetite.
If you are interested in understanding the level of ketosis reached, there are 3 measurement modes available , all of which can be performed either independently or with the help of a nutritionist:
- 1- Test for ketones through urine: they are simple strips, available in pharmacies, which are used to check the presence of ketones in the urine, they indicate the amount of ketones through a coloring scale; it is the fastest but also the least precise mode ;
- 2-Ketone test through the breath: it is a simple tool that you will have to blow into. The detector will measure the acetone levels in your breath. It is generally believed to be more reliable than the urine test.
- 3- Tests that measure ketone levels in the blood: this is the most accurate method to assess your ketosis level. Make a small hole in your finger, just like you want to measure glucose. Clearly these tools, generally used by nutritionists, are slightly more expensive.
Video Interview : Crisitan Disisto, founder of Ketolife, explains in a practical way what are the various ways to measure the level of ketosis reached
Ketogenic Diet vs Traditional Diets: “Pro”
A ketogenic diet is an effective way to lose weight and reduce risk factors for some diseases better described below.
The ketogenic diet is in some cases even more effective than traditional low-fat diets, as shown in the following graph presented by Brehm BJ et al and published in the published in “The Journal of Clinical endocrinology & Metabolism” [ JCEM1 ]
The results we learn from this graph, extrapolated from a major comparative study between diets, show that ketogenic diets in absolute terms of weight loss may be more effective.
These data have been confirmed by most of the scientific literature that dealt with the comparison [ Pubmed10 , 11 , 12]
The graph above shows the higher performances, but let’s not forget that the majority of doctors and nutritionists, in “normal” health conditions or goals, consider the low-fat diet curve to be more physiological, especially in terms of nutrition education.
Ketogenic Diet vs Traditional Diets: “Cons”
As we have seen, many studies have been carried out in recent years to support the great effectiveness of this slimming methodology.
The downside, however, is given by the few studies aimed at the possible health risks of the ketogenic diet repeated or carried on for prolonged periods. Another neglected aspect is the impact it could have on the microbiota of subjects [ PubMed13] .
It is known, in fact, that various components of the diet exert some effects on the composition of the intestinal microbiome , mainly in relation to obesity and inflammatory states. In general, a Mediterranean diet has a positive effect while a diet rich in proteins seems to have harmful effects due to putrefaction phenomena [ PubMed14 ]
Long-term ketogenic diet. Staying on the keto diet long-term can have some negative effects:
- low protein content in the blood
- extra fat in the liver
- kidney stones
- deficiencies of micronutrients
A type of drug called a sodium-glucose cotransporter 2 (SGLT2) inhibitor for type 2 diabetes may increase the risk of diabetic ketoacidosis, a dangerous condition that increases blood acidity. Anyone taking this drug should avoid the keto diet ( PubMed 30 , 31 ].
Also not negligible are the most common and relatively minor short-term side effects of the ketogenic diet which include a range of symptoms such as nausea , vomiting , headache , fatigue , dizziness , insomnia , difficulty in tolerating exercise and constipation, sometimes referred to as keto flu.
There are some side effects of the keto diet that you should discuss with your doctor especially if you plan to follow it for the long term.
Ketogenic diets for diabetes and prediabetes
Diabetes is characterized by changes in metabolism, high blood sugar levels, and reduced insulin function.
The ketogenic diet can help you lose excess fat, which is closely linked to type 2 diabetes, prediabetes and metabolic syndrome ( PubMed15 , 16 , 17 ).
The interesting data emerging from the aforementioned studies are related to the normalization of blood glucose , reduction of loss and improvement of insulin sensitivity .
An interesting study on 349 diabetic patients
A 2019 study published in Ftontiers in Endocrinology involved as many as 349 people with type 2 diabetes [ PubMed 18 ].
Participants, guided for 2 years , especially with the help of telemedicine, were advised to achieve and support nutritional ketosis through the following ketogenic diet interventions:
- Carbohydrates : Sufficient carbohydrate restriction(initially <30g / day, but gradually increased based on personal carbohydrate tolerance and health goals).
- Protein :Participants’daily protein intakewas initially targeted at a 1.5g kg level of a mid-frame ideal weight body and further customized based on biomarkers.
- Fat : Participants were instructed to include sufficient dietary fat in their meals to achieve satiety. Food education has directed the consumption of monounsaturated and saturated fats with a sufficient intake of omega-3 and omega-6 polyunsaturated fats.
- Vitamins and Minerals: Participants were also encouraged to consume sufficient amounts of fluids, vitamins, and minerals including sodium and magnesium, especially if there were any signs of mineral deficiency.
The study found that those who followed the ketogenic diet lost an average of 26.2 pounds (11.9 kg) over a 2-year period.
There were also improvements in blood glucose , insulin , HbA1c , blood pressure , triglycerides , liver function and inflammation, and reduced drug dependence .
These long-term benefits were achieved in conjunction with a reduced prevalence of metabolic syndrome and visceral adiposity. There were no adverse effects on bone mineral density.
If you have diabetes or prediabetes, it may be important to consult your endocrinologist to explore the possibility of introducing the ketogenic diet.
Ketogenic diets for epilepsy
The ketogenic diet actually originated as a tool for treating neurological diseases such as epilepsy, especially in children.
Research in this area is prompted by an old observation that the fasting condition prevents the frequency and extent of seizures. This is due to the fact that in fasting the body produces ketone bodies in abundance, and these substances interfere with the activity of certain areas of the brain, in particular by controlling the electrical discharges that are the basis of epilepsy.
The use of a ketogenic diet, therefore, offers the possibility of treating drug-resistant epilepsy with proven efficacy [ PubMed19, 20 ].
For people with difficult-to-treat epilepsy or people who are unsuitable for surgery, a ketogenic diet remains an important option. Diet choice should be made on an individual basis considering the patient’s age, family circumstances, severity and type of epilepsy.
Article : Read the article by Quotidiano Sanità – “ Epilepsy and the ketogenic diet. Attacks reduction up to 85% of cases “
Pediatric and adult neurologists are increasingly able to identify and refer patients appropriate to the ketogenic diet, which is not used only as a last resort.
Ketogenic diets and other pathologies
We know that excess weight loss can have benefits for a wide variety of different health conditions.
To date, numerous studies have been carried out that try to demonstrate the effectiveness of the ketogenic diet for some pathological stages, such as:
- Heart disease . The ketogenic diet can help improve risk factors such as body fat, HDL (good) cholesterol levels, blood pressure and blood sugar [ PubMed 20 ].
- Cancer . The diet is currently being studied as an additional treatment for cancer because it can help slow tumor growth. [ PubMed 21 , 22 , 23 ].
- Alzheimer’s disease . The keto diet can help reduce the symptoms of Alzheimer’s disease and slow its progression [ PubMed 24 , 25 , 26 ].
- Parkinson’s disease . Although more research is needed, one study found that diet helped improve symptoms of Parkinson’s disease [ Pubmed 27 , 26 ].
- Polycystic ovary syndrome . The ketogenic diet may help reduce insulin levels, which may play a key role in polycystic ovary syndrome [ PubMed 28 ]
For these pathologies there is still no unequivocal and convergent scientific evidence. We will update you when there are interesting news from the search.
Ketogenic Diet: Foods to Avoid
On the ketogenic diet, any high-carb food should be limited. Here is a list of foods that need to be reduced or eliminated on a ketogenic diet:
- sugary foods : soda, fruit juices, smoothies, cakes, ice cream, candy, etc.
- cereals or starches : products based on wheat, rice, pasta, cereals, etc.
- fruit : all fruit, except small portions of berries such as strawberries
- beans or legumes : peas, beans, lentils, chickpeas, etc.
- root and tuber vegetables : potatoes, sweet potatoes, carrots, parsnips, etc.
- dietary or low-fat products : low-fat mayonnaise, salad dressings and dressings
- some condiments or sauces : barbecue sauce, honey mustard, teriyaki sauce, ketchup, etc.
- unhealthy fats : processed vegetable oils, mayonnaise, etc.
- alcohol : beer, wine, spirits, mixed drinks
- sugar-free diet foods : sugar-free candies, syrups, puddings, sweeteners, desserts, etc.
Avoid carbohydrate-based foods such as grains, sugars, legumes, rice, potatoes, candies, juices, and even most fruits.
Ketogenic Diet: Foods to Eat
If you go ketogenic you should base most of your meals on these foods:
- meat : beef, lamb, chicken, pork, rabbit, turkey, cold cuts, game, etc;
- fatty fish : salmon, trout, tuna, mackerel, blue fish, sardines, anchovies;
- shellfish: shrimp, shrimp, lobster, lobster, crab;
- butter and cream;
- cheeses : aged cheeses, mozzarella, goat cheeses, feta; etc.
- yogurt: whole, Greek;
- nuts and seeds : almonds, walnuts, flax seeds, pumpkin seeds, chia seeds, etc.
- healthy oils : extra virgin olive oil, coconut oil and avocado oil;
- avocado : fresh avocado, guacamole;
- low carb vegetables: green leafy vegetables, cruciferous vegetables, eggplant, broccoli, tomatoes, onions, cauliflower, peppers, cucumber, asparagus, green beans, courgettes, celery, spinach, chard etc.
- mushrooms ;
- olives ;
- low carbohydrate fruit: strawberries, lemons, oranges, grapefruits, mulberries;
- seasonings : salt, pepper, aromatic herbs and spices;
- drinks : water, coffee, tea
Base your diet on meat, fish, eggs, butter, nuts, healthy oils, and many low-carb vegetables.
An Example of a Keto Nutrition Program for 1 Week
To help you get started, here’s an example of a ketogenic diet for a week:
- breakfast : vegetarian muffins and eggs with tomatoes;
lunch : chicken salad with olive oil, feta cheese, olives and side salad;
- dinner : salmon with asparagus cooked in butter;
- breakfast : egg omelette, tomato, basil and spinach;
- lunch : almond milk, peanut butter, spinach, cocoa powder, and stevia milkshake (more keto smoothies here) with a side of sliced strawberries;
- dinner : cheese tacos with salsa;
- breakfast : chia pudding with nut milk topped with coconut and blackberries
- lunch : avocado shrimp salad
- dinner : pork chops with parmesan, broccoli and salad
- breakfast : omelette with avocado, salsa, peppers, onion and spices
- lunch : a handful of walnuts and celery sticks with guacamole and salsa
- dinner : chicken stuffed with pesto and cream cheese and a side of grilled zucchini
- breakfast : greek without sugar, whole yogurt with peanut butter, cocoa powder and berries
- Lunch : Tacos wrap of ground beef lettuce with sliced peppers
- dinner : loaded cauliflower and mixed vegetables
- breakfast : cream cheese pancakes with blueberries and a side of grilled mushrooms
- lunch : zucchini and beetroot salad
- dinner : white fish cooked in coconut oil with kale and toasted pine nuts
- breakfast : fried eggs with and mushrooms
- Lunch : Low-carb chicken and sesame broccoli
- dinner : pumpkin spaghetti Bolognese
Always try to rotate vegetables and meat in the long run, as each type provides different nutrients and health benefits.
Aperitifs and “keto” snacks
In case you get hungry between meals, here are some healthy, keto-approved snacks:
- morsels of mozzarella;
- aged cheeses;
- a handful of nuts or seeds;
- one or two hard-boiled or deviled eggs;
- keto-friendly snack bar;
- 90% dark chocolate;
- whole greek yogurt mixed with nut butter and cocoa powder;
- peppers and guacamole;
- strawberries and simple ricotta;
- celery with salsa and guacamole;
- dried meats;
- Raw vegetable pinzimonio;
Tips and tricks for those starting the ketogenic diet
While starting the ketogenic diet can be difficult, there are several tips you can use to make it easier.
- Start by familiarizing yourself with food labels and checking nutrients. In particular, if per 100g of product the carbohydrate content is less than 10g then the food could be for you.
Obviously consider that the ideal condition for those who carry on a ketogenic diet is to eat foods with zero grams of carbohydrates per 100g of product;
- plan meals. Being organized and following a meal plan developed by a nutritionist can help you avoid mistakes and save extra time during the week;
- ketogenic recipes. Many websites, cooking blogs, apps, and cookbooks also offer keto-friendly recipes and meal ideas that you can use to create your own personalized menu;
- delivery and home delivery. Some meal delivery companies also offer keto-friendly options for a quick and affordable way to enjoy keto meals at home;
- lunch break . When you’re short on time, you’re at work, conferences you might also want to consider bringing your own food, which can make it much easier to curb cravings and stick to your eating schedule.
Reading food labels, planning meals in advance, and bringing your own food to work for lunch can make sticking to the ketogenic diet much easier.
Tips for eating out and sticking to the ketogenic diet
Often in many restaurants or pubs it is not easy to find “keto friendly” foods.
Order meat or fish dishes and ask to replace high-carb side dishes such as potatoes with extra vegetables.
Egg-based meals are also a great option, like an omelette, hard-boiled eggs, or scrambled eggs.
If you are in the pub, order a burger by the plate. You can also replace the fries with vegetables. You can add avocado, cheese, bacon, or extra eggs.
Instead of dessert, you can ask for a platter of mixed cheeses or even berries with cream.
Keto diet side effects and how to minimize them
Although the ketogenic diet is generally safe for most healthy people, there may be some initial side effects as your body adjusts.
There is some anecdotal evidence of these effects often referred to as keto flu [ PubMed 29 ]. Based on food reports from some, it usually ends within a few days.
Reported keto flu symptoms include:
- He retched;
- low physical energy;
- mental fog;
- sleep problems;
- feeling faint;
- increased heart rate;
These symptoms usually peak in the first week and then subside after 4 weeks.
To reduce side effects, you can try a low-carb but regular diet for the first few weeks, then switch to the full-fledged ketogenic diet.
This way your body will learn to burn more fat before completely eliminating carbohydrates.
A ketogenic diet can also change your body’s water and mineral balance, so adding extra salt to your meals or taking mineral supplements can help. Also for this it is necessary to consult an endocrinologist or a nutritionist.
At least in the beginning, it’s important to eat until you are full and avoid limiting calories too much. Usually, a ketogenic diet causes weight loss without intentional calorie restriction.
Many of the side effects of starting a ketogenic diet can be limited. Preparing for the ketogenic diet and taking vitamin and mineral supplements may help.
Here are answers to some of the most common questions about the ketogenic diet.
1. Can I ever eat carbohydrates again?
Yes. However, it is important to significantly reduce your carbohydrate intake initially. After a first rigid period it is possible to eat small quantities of carbohydrates sporadically, perhaps on special occasions.
2. Will I lose muscle?
There is a risk of losing some muscle with any diet. However, protein intake and high levels of ketones can help minimize muscle loss, especially if you do sports or fitness constantly [ PubMed 32 , 33 ].
3. Can I build muscle on a ketogenic diet?
Yes, but it may not work as well as with a moderate carbohydrate diet [ PubMed 34 ]. For more details on low-carb or keto diets and physical performance, read this article.
4. How much protein can I eat?
Protein should be moderate, as very high intake can raise insulin levels and lower ketones. About 35% of the total calorie intake is probably the upper limit.
5. What if I am constantly tired, weak or fatigued?
You may not be in full ketosis or are using fats and ketones efficiently. To counter this problem, reduce your carbohydrate intake and revisit the previous points. Supplements such as coconut oil (MCT) or caprylic acid can also help [ PubMed 35, 36 ].
6. My urine smells fruity. Why is this?
Don’t be alarmed. This is simply due to the excretion of the byproducts created during ketosis.
7. My breath stinks. What can I do?
This is a common side effect. Try drinking naturally flavored water or chewing sugar-free gum.
8. I felt ketosis was extremely dangerous. It’s true?
People often confuse ketosis with ketoacidosis. Ketoacidosis is dangerous, but ketosis on a ketogenic diet is usually fine for healthy people. Talk to your nutritionist before starting a new diet.
9. I have digestive problems and diarrhea. What can I do?
This common side effect usually goes away after 3-4 weeks. If it persists, try eating more fiber-rich vegetables [ PubMed 37 ] [ ScienceDirect 1 ]
To date, the specialists in the sector, such as endocrinologists, neurologists, oncologists and general practitioners, prescribe the ketogenic diet for limited periods and especially in selected cases, such as the failure of hypolipidic diets or in the case of particular diseases such as diabetes, epilepsy , cancer, etc.
It is a rather complex dietary regimen where planning and pursuit errors can be paid dearly. For this reason, it is recommended to be followed by nutritionists with specific expertise in the field of ketogenic diets.
- Ask a nutritionist for advice expert in Low Glycemic Index Diets;
- Get advice from an endocrinologist expert in diabetology.
The future of ketogenic diets
We know that weight loss always has system-wide benefits. Further comparative studies of efficacy between traditional hypo-lipid diets and hypo-carbohydrate ketogenic diets on the various pathological statuses are therefore desirable.
Future precision medicine studies could allow the identification of specific phenotypes or genotypes that may indicate best practices for the appropriate use of a dietary macronutrient content (both quality and quantity) as a therapy for the prevention or treatment of ‘obesity.