FAQ: Low-carb & Keto

By Dietdoctor @DietDoctor1

Some questions about low carb and keto are very common. Here you can find answers to them. To jump down to each category of questions, just click the topic:

Do you miss any specific question? Let us know in the comments below.

Weight loss

I'm not losing weight as fast as I want to or I have plateaued. What to do?

There are a few things you can think about in order to lose weight, where the ones that might have the greatest impact are:

Note that as you get closer to reaching your ideal weight, the rate of weight loss will most likely slow down. It's normal to reach a temporary plateau at some point. Also weight fluctuations of several pounds happen every day. This is all OK, just keep on doing what you're doing.

However, if your weight loss stops for many weeks or even months, or if you want to speed it up, here are more things to consider: How to Lose Weight

Do people who stop a low-carb diet and return to their old eating habits regain weight fast? Can low-carb diets cause "carb intolerance"?

When following low-carb diets, people tend to lose more weight than on other diets (on average). So it is logical that when people return to their old diet they might regain more. It is simply a bigger step in the wrong direction, compared to going off other diets.

There's no evidence for the speculation that eating low carb would cause carb intolerance.

However, a temporary " cheat day " may lead to filling up your body's sugar stores (glycogen), which binds more water, adding weight. This water weight (perhaps 1-2 pounds or slightly more) quickly disappears within days when you go low carb again.

How do I STOP losing weight?

For some people it is very easy to drop a significant amount of weight on low carb. Normally weight loss stabilizes within the normal weight range, as long as you eat when hungry and don't starve yourself.

However, if you're concerned that you're losing too much weight, then you have a few options:

  • Eat often, at least three times per day, including plenty of protein, and lift weights to put on muscle.
  • Eat slightly more carbs (like low-glycemic fruits, sweet potato, etc.) to put on a bit more fat.

To summarize, there's normally no need to stop a low-carb diet to stop losing weight. This will happen anyway, as you reach what your body perceives is the right weight for you.

Should I want to, is it possible to gain weight on low carb?

It's hard for most people to gain fat mass on low carb. But it's clearly possible to add lean mass, like muscle. Check out our guide here:

How to gain weight on low carb

Diabetes and blood sugar

Is a low-carb diet good for people with type 2 diabetes?

Yes. People with type 2 diabetes have a hard time regulating sugar in the body. The pancreas produces a lot of the hormone insulin in order to move sugar out of the blood and into the body's cells. More and more insulin may be required for this, leading to a vicious cycle resulting in insulin resistance and consequences of high insulin (including weight gain).

By following a low-carb diet, you may reduce blood sugar levels, insulin levels and your need for medication. So yes, a low-carb diet can be very beneficial for patients with diabetes type 2. It can even start reversing the disease.

Note though - this is very important - that if you are taking medications, especially insulin, you need to monitor your blood sugar levels closely when starting a low-carb diet, and adapt (lower) doses as appropriate to avoid low blood sugar. You should of course consult with your doctor, as ideally he or she has knowledge about how to reduce medications on a low-carb diet. Read more about starting keto or low carb with diabetes medications.

Learn more:

Is a low-carb diet good for people with type 1 diabetes?

Yes. It may help stabilize blood sugar levels and reduce the need for high insulin doses (also helping with weight loss if needed, as a bonus).

Be very careful when starting a low-carb diet, as you'll have to adapt your insulin doses. Big changes may be needed, e.g. a reduction by 30-70%, depending on your specific situation. This can only be done by testing sugars and adapting insulin doses to your specific needs.

Learn more: Type 1 diabetes

Should I be worried about low blood sugar on low carb or while intermittent fasting?

Generally, you don't have to be worried as long as you feel fine and are not taking any diabetes medication. Blood sugars can be slightly lower than normal on a low-carb diet, especially when you are in ketosis. In this situation the brain can rely on ketones for fuel and does not have quite the same need for glucose. Learn more: Food for thought: Does the brain need carbs?

So if you feel great, you probably have all the blood sugar that your body needs. If you're not feeling well, you should eat something straight away, and break any fast.

If you're on medication, like insulin or certain diabetes medications, low blood sugar is a sign that you may have to reduce your dosage (especially if you get any symptoms).
Learn more: Starting keto or low carb with diabetes medications

High blood sugar in the morning - why?

Elevated morning blood sugar is a common concern. This is known as "the Dawn Phenomenon" and occurs due to hormonal effects in the early morning hours. It may possibly be even more pronounced on a low-carb diet, compared to other diets.

Many people get surprised as their average blood sugar (measured as HbA1c) goes down nicely on low carb, blood sugar is great during the day... but morning sugar remains elevated.

This is normally a natural phenomenon, caused by a morning rise in cortisol and other hormones that cause the liver to release glucose, thus raising blood sugar levels. This can be thought of as a way for the body to prepare you for getting active again, after sleeping.

Learn more: The dawn phenomenon - why are blood sugars high in the morning?

Food, hunger and cravings

Can I eat XYZ?

There are a few foods that don't contain too much carbohydrate, but which might not be optimal for health, cravings, and weight loss reasons. These include:

    Low-carb cookies/bread/pasta. This is not a good idea, given that the vast majority of these low-carb "carb substitutes" are packed with carbs. Examples:
I'm constantly hungry and craving food in between meals. What should I do?

You're not supposed to get hungry between meals on a low-carb diet. Here's what you should try: Eat more food at meals, especially more fat.

Add more fat to your meals, until you feel satisfied. Add butter to food. Add olive oil to salads. And perhaps check out our low-carb condiments recipes for more inspiration.

Also make sure to have a delicious and high-quality source of protein with most meals.

You're not supposed to be hungry all the time. If you are, you're not eating enough fat and protein.

If I'm lowering carbs and even limiting protein... what do I eat?

Usually, there is no need to limit protein, it is fine to eat a "normal" amount. Just don't overdo it with protein. Remember that LCHF is supposed to be a low-carb and high- fat, diet, not a high-protein diet. Read our guidelines for individualized protein intake.

For a standard low-carb meal, you simply remove the carb-heavy ingredients, like rice. You then add some vegetables and some healthy oil or fat-based sauce. But there are plenty of other options.

Here are many delicious examples of what a meal can look like: Low-carb recipes.

I'm craving carbs. Can I have a cheat meal - or a cheat day - once in a while?

Only you can decide - cheating can be a good idea for some, and a terrible idea for others. It also matters how you cheat. Check out our guide:

A guide to low-carb cheating
I'm really struggling with cravings for carbs, even when I'm not hungry. What should I do?

Carb cravings can be tough. Fortunately, avoiding sweets and other foods that trigger foods can be a very effective solution.

Learn more about sugar and carb addiction
Do you need to eat resistant starch on low carb to feed your gut bacteria?

At this time it's unknown, but there appear to be some potential benefits of doing so

Cholesterol

I have high cholesterol. How can I lower it?

If your cholesterol is high you may want to do something about it. If so, check out our guide on elevated cholesterol on a low-carb diet.

Elevated cholesterol on low carb
Is it bad to have high cholesterol?

High cholesterol can be a risk factor for heart disease. Furthermore, the risk of heart disease is also influenced by many other things, like smoking, blood pressure, and blood sugar control. When it comes to cholesterol it's important to not just look at the total level, but also at the rest of the cholesterol profile, e.g. HDL (higher is better) and triglyceride (lower is better) levels.

Learn more about cholesterol
Should you be on statins?

Statins are mainly a good idea to reduce risk of heart attacks in people who already have heart disease, or who have a very high risk of heart disease. Ask your doctor how big the benefits are likely to be for you.

There are also steps to improve your cholesterol profile without taking medications. See this guide about lowering cholesterol naturally.

Medications

I'm taking this medication, will it prevent weight loss?

There are certain medications that might make it harder to lose weight, but not necessarily prevent weight loss. The most important are:

  • Insulin
  • Other diabetes medications
  • Cortisone and other steroids

There are other medications which too might interfere with weight loss. You can read more about that here: How to lose weight: 10. Review any medications

If you're doing everything right and not losing weight while on one of these drugs, it might be a good idea to consult your physician to see if it would be possible for you to either lower your dose or quit the medication altogether.

The science behind low carb

Is there scientific proof that LCHF is good for weight/blood sugar/cholesterol/blood pressure?

Yes. Learn more

Also feel free to watch this interesting interview with a doctor who's been doing some high-quality research on the topic:

Does insulin play a role in weight gain / loss?

Yes, insulin - the fat-storing hormone - appears to play an important role in weight gain and the development of common obesity.

Learn more
Why are Asian people thin, despite eating rice?

First of all, there is now a huge epidemic of weight problems and type 2 diabetes in countries like China and India. So it's no longer true that these people are necessarily "thin."

But it's true that these countries have traditionally had very lean populations. This is probably because they don't eat a lot of sugar or refined starch, plus a few other reasons. Learn more

Common fears about low carb

For our full guide to low-carb fears, check out this guide:

Top 14 low-carb fears (and whether you should be worried)
I fear XXX...

What is the biggest fear that people have when starting a low-carb diet? We recently asked our members this question. Here are the results:

Other answers include some brave people having no fear at all, while others have concerns about safety, losing sports performance, as well as the fear of losing too much weight.

So what can be done? Here's our guide to conquering these fears

Is saturated fat dangerous?

Modern science suggests that the fear of saturated fat may have been a mistake. Learn much more in the interviews below, or check out our full user guide to saturated fat.

Will the brain stop working without carbohydrates?

Certainly not. The brain runs fine on carbs, but it runs equally fine on ketones, made from fat. In this way you use your very energy-hungry brain to burn fat for you, 24-7. Not a bad thing.

Check out the video to the right for more details from some very smart doctors

You can also read our guide: Food for thought: Does the brain need carbs?

Can't red meat give you cancer?

This is highly unlikely, although favoring unprocessed meat is the best choice. On the other hand, replacing meat with processed carbs may be one of the worst things that you can do for your health and weight.

Another interesting interview topic:

Read more: Do unhealthy meat eaters live shorter lives?

Is salt dangerous?

As long as your blood pressure is under control, moderate amounts of salt are likely safe for most people. Learn more

Can you get osteoporosis (weak bones) by eating low carb?

No, as long as you eat enough to meet your nutrition needs - which is true for any diet. A low-carb diet can provide everything you need to keep bones strong and healthy. Learn more

What about gallstones and LCHF?

High-fat food can give you short-term trouble if you already have gallstones. Low- fat food may promote gallstones in the long term. Learn more

Can you get hypothyroidism on a very low-carb diet?

No, this is very unlikely on a well-formulated low-carb diet, meaning that you replace the energy from carbs by eating more fat. In scientific studies on LCHF no problems with the thyroid have occurred, and low-carb doctors generally report seeing no new thyroid issues in patients going strictly low carb.

However, starvation can lead to hypothyroidism, and if you remove carbs AND fat from your diet you will be starving. So you do need to eat carbs or fat to fuel your body.

Learn more about low carb and the thyroid

Low-carb side effects

I'm getting XYZ side effect - should I be concerned?

There are a few side effects that are quite common during the first few weeks when your body adapts to a low-carb diet. These are usually temporary, and nothing to worry about (even if they can be unpleasant). These include:

  • Induction or keto flu
  • Dizziness
  • Leg cramps
  • Constipation
  • Bad breath
  • Heart palpitations
  • Reduced physical performance.

The trick that usually works in ameliorating these problems is drinking water with salt (and maybe some squeezed lemon).

However, if you use blood pressure medications and you feel dizzy, it might be because low-carb diets can reduce blood pressure and you may thus need to lower your medication.

If you want to learn more about how to treat these specific side effects and other less common ones, use this guide:

Common low-carb side effects & how to cure them

Ketosis, ketones and ketogenic diets

Is it dangerous to be in ketosis?

No, ketosis is a natural state, and normally safe. Learn more: The complete guide to ketosis

People often confuse ketosis with ketoacidosis. This is a dangerous state, caused by a shortage of insulin, that mostly happens to people with type 1 diabetes who take too little insulin.

There are also certain instances when you might need to be extra careful, such as during breast feeding or if you're on some other medications for diabetes.

Why am I not in ketosis despite eating low carb?

The most common reason why people don't achieve ketosis is eating too many carbs (maybe because of hidden carbs, or the dreaded carb creep, where after a while you eat more and more carbs without noticing).

Another big obstacle to getting into ketosis can be eating too much protein. To be in optimal ketosis, you should eat around 1.2 to 1.5 grams of protein per kg of body weight (or ideal body weight, if you are overweight).

Insulin resistance can also make it harder to get into ketosis.

Learn more about how to get into ketosis
Do I need to be in ketosis to lose weight, or to burn fat?

No, you don't have to be in ketosis to lose weight. And your body is always burning some fat, whether you are in ketosis or not. The difference is that in ketosis you burn more fat.

Top tips on how to lose weight A quick guide to ketogenic diets

Can XYZ follow a low-carb diet?

Can people with diabetes eat low carb?

Yes. In diabetes there is too much sugar in the blood, so by eating less carbohydrates that turn into sugar in the body, you can start reversing type 2 diabetes.

People with type 1 diabetes can also benefit from low carb. Learn more in our guide to type 1 diabetes.

However, if you take insulin for either type of diabetes, you'll have to monitor your blood sugars closely to avoid hypoglycemia (low blood sugar), since the need for insulin drops on low carb.

How to reverse your type 2 diabetes
Is a low-carb diet suitable for someone who has had a gastric bypass surgery?

Yes, it can be. Here's just one of many happy people who have tried it: "What an amazing journey"

Can people that have had their gallbladders removed eat low carb?

Yes, although they may need to increase their fat intake a bit more gradually. Learn more

Can kids eat low carb?

Sure. Children are better off ditching sugars, starches and highly processed food, and eating whole food such as healthy fats, meat, poultry fish, vegetables, nuts and low-glycemic fruits and berries instead.

This is a very nutritious diet for their growing bodies. But there is usually no need for children to follow a strict low-carb diet. Just let them have healthy, minimally processed food.

How to raise children on real low-carb food
Can women who want to get pregnant eat low carb?

Yes. It can even be a good way to boost fertility, since a common cause of infertility (PCOS) can be caused by elevated insulin levels, caused in part by consuming too many dietary carbohydrates. Learn more: How to potentially reverse PCOS with low carb

Can women eat low carb during pregnancy?

Based on what is known, eating a well-balanced LCHF diet is safe when pregnant. Many people have done so successfully. However, no scientific studies have ever investigated putting women on low-carb diets during pregnancy, meaning it's hard to know for certain.

For this reason we recommend not doing a strict low-carb diet during pregnancy, unless there is a specific medical reason to do so. It may be wise to eat a more liberal low carb diet with more than 50 grams of net carbs per day.

When you're eating minimally processed low-carb food such as natural fats, meat, poultry, fish, seafood, vegetables and berries, you give both your own body and the baby enough nutrients to be healthy.

Learn more: Is low carb safe during pregnancy?

Can women eat low carb during breastfeeding?

A diet consisting of natural whole food is a great way to give both yourself and the baby plenty of nutrients to stay healthy and keep excess weight off. However, we don't recommend a strict low-carb diet, since in very rare cases it might cause a condition known as ketoacidosis.

Our recommendation is that women make sure that they eat at least 50 grams of net carbs per day when breastfeeding in order to avoid this rare complication.

Eating low carb when breastfeeding
Can healthy, slim people eat low carb?

Yes, definitely. There will always be health benefits to eating minimally processed food and ditching refined food, sugars and starches. If you're healthy and slim you can take a more liberal approach to your carb intake, however.

How much should I eat?

OK... but how much should I eat?

The short answer is that you should eat when you're hungry, and stop when you're full.

You shouldn't stuff yourself full or let yourself get uncomfortably ravenous between meals. This is usually easy for people who stick to a low-carb diet based on whole food. Counting is usually overcomplicating things. It's better to instead (re-)learn how to listen to our bodies.

Why don't you advise people to count calories?

Because it's impossible to know exactly how many calories your body needs for weight loss. Insulin also plays an important role in whether we gain or lose weight. By focusing on doing things that lower insulin - the fat-storing hormone - you can reduce weight without calorie counting.

It's much more effective to eat an LCHF diet, intermittent fast, sleep/de-stress and do resistance training (which can all help reduce insulin) rather than spending time counting calories.

Counting and restricting calories is not only extra work and usually ineffective in the long term. It often also leads to hunger, and giving up.

Learn more: Should you count calories on a low-carb or keto diet?

How many carbs should I eat?

When trying to lose weight, eating very few carbs is usually most effective. Ideally, consume less that 20 grams of carbs per day (a strict low-carb or keto diet).

People that are healthy and slim usually don't have to go that low. They will be just as well off with moderate (20-50 grams) or liberal (50-100 grams) low-carb diets.

Learn more: How low carb is low carb?

How much protein should I eat?

Once again, there is usually no need to count protein intake as long as you stick to natural low-carb food and eat until satisfied. If you're losing weight (if that is your intention) or maintaining a healthy weight, there is no need to worry about having too much protein.

Learn more: How much protein should you eat?

How much fat should I eat?

If you're limiting carbs and eating moderate amounts of protein, then you should eat enough fat to feel satisfied. Once again, you shouldn't eat so little fat that you're hungry between meals, but you shouldn't force feed yourself until you're stuffed either.

Learn more: How much fat should I eat?

Best of luck!