Last Updated on October 4, 2019 by Michael Joseph
Over recent years, ketogenic diets have become increasingly popular.
The diet is otherwise known as ‘keto,’ and it’s high in fat and extremely low in carbs.
Generally speaking, low carb diets can potentially have numerous benefits.
But there are a few things to be aware of, such as the benefits, best foods to eat, foods to avoid, possible dangers and side effects.
This guide will show you all of these things.
Also, the guide provides sample keto meal plans, snack ideas, and guidance on how to implement the diet in a healthy way.
What is a Ketogenic Diet?
Ketogenic diets are a way of eating that focus on strictly limiting carbohydrate.
And if implemented well, research suggests they can be beneficial.
By and large, those following a keto plan eat higher amounts of fat, moderate protein, and a very small amount of carbs.
As long as you keep carbs very low, then keto is possible on a range of macronutrient ratios.
However, the usual macro range looks something like this:
- Carbohydrate: 5-10%
- Fat: 60-75%
- Protein: 20-30%
How do keto diets work?
When you keep carbs very low for an extended period, the body enters nutritional ketosis.
Ketosis refers to a state in which the body starts burning fat for energy rather than carbohydrate.
On a typical high carb diet, the body burns glucose. In contrast, the ketogenic diet encourages the body to start using ketones for fuel.
Ketones are a type of molecule that our liver produces during times of carbohydrate restriction (or overall low food intake).
The human body can use both glucose and ketones for fuel.
How many carbohydrates should I eat?
Respected low carb researchers Jeff Volek and Stephen Phinney advise aiming for an upper limit of 50 grams total carbs. Below this number is also widely accepted as a ketogenic diet (1).
Generally speaking, you can eat this amount of carbohydrate and still be in ketosis.
However, everybody is different, and the exact number will depend on the individual – it might be 35g, or it might be 70g.
There are even some people who adopt a zero carb diet; however, for the majority of people, this is far too restrictive.
How can I tell I’m in ketosis?
There are many signs which suggest you might be in ketosis:
- Rapid weight loss, usually due to a drop in water weight
- Some people report feelings of greater satiety and reduced food cravings
- Possible short-term side effects such as bad breath and fatigue
Potential Benefits of a Ketogenic Diet
Keto wouldn’t be so popular if it didn’t have benefits—and there are many of them.
Blood sugar and insulin levels improve:
As ketogenic diets cut out sugar and carbohydrates, blood sugar levels tend to fall. In recent times, many people with diabetes are successfully managing their condition using a keto plan (2).
Have you ever tried an extremely low-calorie diet before? If you have, you may remember how difficult it can be to control food cravings.
However, keto diets encourage satiety due to their higher fat and protein content (3).
Reductions in triglycerides:
Triglycerides are one of the major risk factors for cardiovascular disease. Carbohydrate restriction leads to lower triglyceride levels (4).
Keto may be beneficial for managing certain brain-related diseases and illnesses:
Ketogenic diets can be therapeutic for a variety of brain conditions, whether severe chronic diseases or mild problems.
A significant increase in HDL levels:
Lower intake of carbohydrate combined with higher fat consumption tends to increase high-density lipoprotein (HDL) levels.
Possible benefits for Alzheimer’s disease:
Further research is necessary, but some scientists believe that ketogenic diets may help by supplying the brain with ketones, which it can use for energy.
Reduction in blood pressure:
High blood pressure (hypertension) is a significant risk factor for cardiovascular disease and stroke.
However, one thing that not many people realize is that refined carbohydrate intake has an effect on blood pressure – possibly more so than sodium.
Some people find it enjoyable
And this last one’s pretty obvious. What sounds more appealing to you: low-fat crackers, skim milk, and a fat-trimmed chicken breast? Or steak, cheese, and some dark chocolate? Everyone is different, sure, but a lot of people would prefer that second group of foods.
What Foods Can I Eat on Keto?
The first thing to remember is that despite having a ‘restrictive’ reputation, there are many things that you can eat on keto.
For extra guidance, see this keto shopping list.
Here are some tables showing a list of suitable foods.
Milk contains too many sugars in the form of lactose, but aside from that most dairy foods are ideal.
|Clotted Cream||Cottage cheese|
Eggs, Meat, and Poultry
You can include all meat and poultry in a keto plan– preferably a wide variety of cuts, including bone-in meats.
|Bacon||Beef – all cuts|
|Eggs||Fermented Meats (prosciutto, salami)|
|Turkey||Venison and wild game|
Fats and Oils
While any fat is technically suitable for a ketogenic diet, it’s better to avoid industrial vegetable oils.
Here are some healthy fat sources:
|Coconut Oil||Extra Virgin Olive Oil|
|Lard||Macadamia Nut Oil|
|Red Palm Oil||Tallow|
There are countless edible fish and here are some of the commonly available ones.
*Best sources of omega-3 **High in both omega-3 and mercury
Fruit (low sugar)
Since ketogenic diets require carbohydrate intake to be very low, most fruits are unsuitable.
However, there are plenty of low sugar fruits that are perfectly fine in moderation.
There are also many different types of berries which are okay in moderation.
Most nuts are great for a ketogenic diet, but cashews, chestnuts, and pistachios are too high in carbohydrate.
Nuts are very energy-dense, so a handful should be enough (1 ounce/28grams)
Here are the best low-carb choices:
Personally, I’m not a fan, but seeds are also a reasonably nutritious option.
Aim for about a handful / 1 ounce / 28 grams.
|Hemp Seeds||Pumpkin Seeds|
|Sesame Seeds||Sunflower Seeds|
Shellfish and Seafood
Generally speaking, lower carb veggies should be the focus: cruciferous veg and leafy greens.
The plants that grow above ground have the lowest carb count, while vegetables growing underground tend to have more.
However, a small amount of below-ground vegetables should be okay if you factor them into your total carb count.
|Beet Greens||Bell Peppers|
Keto Snack Ideas
In addition to the above food groups, there are a number of convenient snacks which are suitable for keto.
Here’s a list to give you a few ideas:
- Berries and cream: Your choice of berries in a bowl with some heavy cream.
- Boiled eggs: If you have any feelings of hunger, a few boiled eggs does a great thing for satiety.
- Celery with cream cheese: Spread some cream cheese on a few stalks of celery for some nutrients and fat-soluble vitamins.
- Cheese and Prosciutto: If you’re craving some finger-food, then cheese and prosciutto is an excellent option. Add a glass of red wine if you like.
- Dark chocolate: 85% minimum.
- Guacamole salad: Mash some guacamole and add in your ingredients of choice.
- Keto milkshake: blend some coconut milk alongside some cacao and a natural (ish) sweetener such as erythritol. Another good option is to use fresh berries for a fruit milkshake.
- Pork rinds: Crispy pork goodness that you can easily make at home.
For anyone who struggles to understand which foods are well suited to a ketogenic diet, there is an impressive new application called Nutrita that can help.
The app tells you the nutrient quality and insulin index of each food in addition to a “keto score” – it’s definitely worth checking out.
Foods to Avoid on Keto
Due to the nature of the ketogenic diet, carbohydrate content in food should be low — ideally around 5-10% or below.
For a keto-friendly diet, it is better to avoid grains, starches, sugars, and other high-carb plant foods.
Below you can see a list of foods to avoid:
- Dried fruit (a slight amount is OK, but best avoided)
- Fruits high in carbs (banana, mango, papaya, etc.)
- Fruit juice
- Grains (bread, oats, pasta, rice, etc.)
- Low-fat processed foods
- Milk (a very small amount is OK)
- Sugary foods in general
- Sweet wines/sugary alcohol in general
- Tubers such as parsnips, potatoes, and sweet potatoes
And these foods are technically ‘ketogenic,’ but it’s better to avoid them for health:
- Low-carb processed foods: they may be low-carb, but they’re usually full of additives.
- Vegetable oils
Not ready to give up alcohol?
If you like drinking from time to time, then that is no problem – there are many low carb alcohol drinks out there.
Spirits and dry red wine are two of the best choices.
Keto versions of high-carb foods
While it’s better to stick with nutrient-dense foods like meat, fish, and vegetables, many people like a treat from time to time.
And if you want to be ‘keto’ yet still have a pizza, some bread, or even a piece of cake – it’s possible.
There are many delicious low-carb recipes available for all of these things, and there are hundreds on Pinterest.
A Basic Ketogenic Meal Plan
Not sure about how you can put some meals together?
Here are some breakfast, lunch, and dinner ideas for every day of the week.
- Bacon and Eggs: Several slices of bacon, some fried eggs, mushrooms, and a grilled tomato.
- Mackerel and sauteed spinach: A baked or steamed fillet of mackerel with some leafy greens sauteed in butter.
- Greek yogurt, nuts, and berries: Greek yogurt is a deliciously creamy high-fat yogurt. Try combining it with some berries and nuts for a tasty breakfast.
- Omelet: A cheese and vegetable omelet using your favorite veggies.
- Boiled Eggs: Several boiled eggs, some cheese, and an avocado.
- Scrambled Eggs: Scrambled eggs with some meat and veggies of your choice.
- Ham, egg and cheese melt: A ham, melted cheese, and egg sandwich. While bread isn’t keto-friendly, you can use a low-carb bread recipe such as cloud bread.
For more ideas, see these keto breakfast recipes.
- Chicken Salad: Diced chicken, salad greens, cherry tomatoes, balsamic vinegar, and extra virgin olive oil.
- Finger Food: A handful of nuts, slices of cheese, and some berries.
- Cloud Bread Sandwich: A ham, cheese, and salad cloud bread roll.
- Chicken Soup: Chicken, stock, some cream, pepper, salt, and mushrooms. And if you want to eat it hot in the office, then it’s possible if you use a mini portable oven.
- Zoodle Carbonara: First, you need some zoodles, and then add cream, ham, egg, and seasonings. Tastes better warm!
- Beef and Tomato Soup: Simmer beef, onion, diced tomatoes, mushrooms, and herbs of your choice for about 1 hour. This meal can be reheated later if eating away from home.
- Low Carb Sushi Roll: Instead of using rice in the nori wraps, use cream cheese instead. Then add some sashimi of your choice (salmon tastes good!).
- Pork Chops: A pork chop cooked with onion and garlic, and some buttered asparagus.
- Cream Salmon: A fillet salmon covered in coconut cream cheese sauce, with some broccoli and mushrooms.
- Steak: A piece of steak with mushrooms, garlic, and green beans.
- Frittata: A cheese, mushroom and vegetable frittata.
- Sausages: Some (real meat) sausages, alongside some mashed rutabaga with butter and sauteed garlic and onions.
- Chicken Curry: Curries are a great meal for ketogenic diets because they are mainly fat and protein. All you have to do is skip the rice.
- Low Carb Pizza: Make a fathead pizza; it tastes great, and it’s reasonably healthy.
For keto on the go, then look for any meat-based restaurants.
A steak or piece of meat/fish along with some vegetables is suitable, and you can find restaurants offering this almost everywhere.
There are two possible things to mention here, and these are ketoacidosis and hypoglycemia.
Firstly, there is a lot of fearmongering about ketoacidosis and ketogenic diets.
Generally, this comes from people who don’t know the difference between ‘ketosis’ and ‘ketoacidosis.’
As previously mentioned, ketosis is a natural state in which the body starts to burn ketones (fats) for energy instead of glucose.
In contrast, ketoacidosis is a potentially life-threatening condition when the body doesn’t make enough insulin and ketone levels become abnormally high.
However, in low carb diets, the production of ketones is “regulated, controlled, and harmless” (13).
The condition is otherwise known as diabetic ketoacidosis (DKA), and usually, results from poor management of type 1 diabetes which can lead to dangerous ketone levels (14).
It’s very unlikely for a healthy person who produces sufficient insulin to experience ketoacidosis (15).
However, if you suffer from diabetes then always consult your doctor and conduct thorough research before a dietary change.
When first beginning a ketogenic diet, experiencing hypoglycemia (low blood sugar) is a possibility.
With this in mind, it’s important to know exactly why it occurs and how to avoid it:
- Hypoglycemia happens when blood sugar levels drop to extremely low concentrations (approx: <70mg/dl) and it can cause fatigue, lightheadedness, and dizziness (16).
- It can occur when suddenly going from a high-carbohydrate diet to very low carb (17)
- One reason is that of a huge drop in blood sugar levels in people who are used to having higher blood sugar.
- Hypoglycemia is a lot more common in people with diabetes or a certain degree of insulin resistance (18).
In the initial stages of a ketogenic diet, it may be helpful to eat regularly rather than fasting for extended periods of time.
Hypoglycemia can be dangerous, so if you are experiencing it, then it may be worth consulting a low-carb friendly doctor.
And this is especially the case if you have diabetes; for any medical issues, it is always better to be safe than sorry.
Side Effects To Be Cautious About
Firstly, it is worth noting that many of the side effects of keto are due to not researching the diet properly before starting it.
For this reason, it is important to be aware of the typical mistakes people make.
Being in ketosis can also cause several minor side effects, so if you have just started a ketogenic diet then look out for the following;
Many people report lower tolerance of alcohol on a ketogenic diet, sometimes dramatically so.
Solution: Firstly, don’t drink too much or on an empty stomach. And if you’re just starting keto, then carefully monitor how you feel when you drink.
When the body enters ketosis and starts burning fat (ketones), chemicals in the breath such as acetone may cause bad breath (19).
Solution: Waiting; for many people, this bad breath only lasts for the first week or two of a ketogenic diet. While it persists, you can use breath fresheners to hide the scent.
Cramps, Fatigue, Induction Flu, and Low Energy
People new to keto often experience cramps, particularly in the legs and feet. Additionally, many people feel fatigued, tiredness, and low energy.
Solution: These symptoms are usually the result of an electrolyte imbalance, especially concerning magnesium, potassium, and sodium.
Don’t worry because it is common in the early stages of ketosis, due to the body releasing significant amounts of water (and salt) as carbohydrate intake (and insulin) drops.
Make sure you are getting enough of these micronutrients. There are also greater needs for sodium on a ketogenic diet, so increase salt intake by liberally salting your food.
Heart palpitations are another typical side effect in the first few weeks of a ketogenic diet. The palpitations could be due to mild dehydration or an electrolyte imbalance.
Solution: Drinking more water to ensure adequate hydration, and increasing salt, magnesium, and potassium intake usually eases heart palpitations.
However, as the cause can be any number of issues, then see a doctor if you want to make sure.
Ketogenic Diets Can Raise LDL Cholesterol
As previously mentioned, ketogenic diets can have a positive effect on several cardiovascular risk factors, such as blood pressure, blood glucose, HDL, and triglycerides.
However, for some people, high-fat diets can increase LDL levels (20).
While some researchers believe low-carb improves cardiovascular risk by increasing HDL and triglycerides, others still worry about the potential rise in LDL levels.
Since this issue is an area where research is ongoing, some people may prefer to err on the side of caution if a ketogenic diet results in high LDL levels.
Of course, this should be discussed with a physician for those that have any concerns.
Here are some nutritional considerations regarding LDL;
- It tends to be saturated fat that causes LDL to rise. Diets that are higher in foods like fish, nuts, avocados, and olive oil may not have this effect.
- Certain fiber supplements, such as psyllium husk, can lower LDL levels (21).
There’s no perfect way of eating that fits everybody’s lifestyle and personal circumstance.
While some prefer very low carb diets, others feel better suited to paleo, whole foods, or even vegetarian diets.
However, keto is a healthy dietary system that focuses on real, nutrient-dense foods.
But just one caveat:
Due to the potential side effects, make sure you research how to implement the diet successfully before you start.
Weight loss very much depends on the formulation of any diet – see these reasons for not losing weight with keto for an overview.
What does the research say about ketogenic diets and weight loss?