Low-carb (LCHF): guide, risks and benefits

What is a low-carbohydrate diet (LCHF)?

A low-carbohydrate diet involves a high intake of fat, a moderate to high intake of protein, and a clearly restricted intake of carbohydrates. The aim is to reduce the body’s reliance on glucose as a fuel source and instead increase the use of fat for energy.

Foods often included are:

• meat and processed meats, for example sausages and minced meat
• fish and seafood, poultry, eggs and cheese
• high-fat sauces, such as butter, coconut fat and béarnaise sauce
• full-fat, plain dairy products such as cream, crème fraîche and full-fat yoghurt
• nuts and seeds
• low-carbohydrate vegetables, for example leafy greens, avocado and broccoli

The diet can be structured in different ways depending on how much carbohydrate is restricted. It can be stricter or more moderate, and is often adapted to individual goals, health and personal preferences.

For some people, a low-carb approach can be relatively easy to start, but how easy it is to follow over time varies and depends on lifestyle and individual circumstances.

What can you eat on LCHF?

With a low-carbohydrate approach, the main focus is on significantly reducing carbohydrate intake. As long as total carbohydrate intake stays low, there are generally no other rules – for example, the diet often does not take fat quality into account.

Common foods include meat, processed meats, fish, seafood and eggs, which provide both protein and fat. Full-fat dairy products such as cheese, butter and cream are also common, along with various high-fat sauces. Nuts, seeds and avocado also feature, together with low-carbohydrate vegetables such as broccoli, cauliflower, spinach and courgette. Fruit is usually limited because of its carbohydrate content, but berries may sometimes be included in small amounts.

How many carbohydrates on LCHF?

How many carbohydrates you eat per day on a low-carb diet depends on how strictly you choose to follow it. There are stricter versions where carbohydrate intake is kept very low, and more moderate versions with a slightly higher intake. Some people prefer very low levels, while others do better with a little more.

It’s also common for sugar to be completely excluded, for example in coffee, and replaced with a small amount of fat such as butter or coconut oil to avoid carbohydrates.

It’s important to remember that carbohydrates are not only found in foods like bread, pasta and rice, but also in fruit, vegetables and dairy products. That’s why it can be helpful to read food labels to keep track of total carbohydrate intake. Being aware of how much carbohydrate you’re having makes it easier to adapt a low-carb approach to your individual goals.

How does a low-carb diet (LCHF) work for weight loss?

A low-carbohydrate diet can be an effective approach for weight loss, especially at the beginning. When carbohydrate-rich foods are restricted, energy intake often decreases spontaneously, without having to count calories.

Many people also experience rapid weight loss in the first few days, mainly because the body’s glycogen stores in the liver and muscles are depleted. Since glycogen binds water, total body water decreases as well. At the same time, bowel contents may reduce when fibre intake drops. This can lead to quick changes on the scales and may feel motivating.

When the body uses fewer carbohydrates for energy and more fat, fat oxidation increases. However, fat oxidation is not the same as weight loss – it simply describes where the body gets its energy from. To lose weight, you always need an energy deficit, meaning energy intake is lower than energy expenditure. This applies regardless of which diet or eating pattern you choose.

More fat per day

When following a low-carbohydrate diet (LCHF), daily fat intake often increases, because fat becomes the primary energy source and can make up a large proportion of meals.

Within low-carb approaches, there are generally no specific recommendations about fat quality. At the same time, it’s important to ensure an adequate intake of essential fatty acids, such as omega-3 and omega-6, and to eat enough vegetables and fibre to keep the diet as nutrient-rich and balanced as possible.

What does research say about LCHF?

There may be several benefits to eating low-carb (LCHF). It can often support weight loss, partly because carbohydrate-rich foods that are energy-dense and easy to overeat (such as pizza, burgers, chocolate and ice cream) are reduced. When these are replaced with protein-rich low-carb options like meat, fish, poultry and eggs, satiety may increase, which can lead to a lower energy intake and weight loss.

There is also scientific evidence that, over a limited period of around six months, LCHF can be more effective for weight loss than a low-fat diet in people living with obesity. Weight loss in people with severe overweight or obesity is, in most cases, associated with improvements in various health markers.

Benefits of LCHF

Some commonly mentioned benefits of a low-carbohydrate diet (LCHF) include:

• increased satiety both after meals and between meals
• improved glucose control in some people
• a clear dietary framework that may feel easier to follow
• reduced cravings for sweet foods

People with type 2 diabetes are one group that may benefit in some cases, as reducing carbohydrate intake can make it easier to reach recommended targets for blood glucose control.

Drawbacks of LCHF

Even though low-carb (LCHF) can work well for some adults, there are risks and challenges:

• Difficulty sticking with it long term: some people find it hard to maintain LCHF over time. Adherence often declines after 6–12 months, which in some cases can lead to weight regain.
• Higher saturated fat intake may affect blood lipids: a high intake of saturated fat can raise LDL cholesterol in some people. Some individuals are particularly sensitive to this effect.
• Risk of nutrient shortfalls: because foods such as fruit, wholegrains and pulses are often limited, intake of fibre, vitamins and minerals may be low.
• Temporary adjustment symptoms: when carbohydrate intake is reduced sharply, some people experience tiredness, headaches or difficulty concentrating at first. Responses vary between individuals.
• Not suitable for everyone: strict low-carb diets don’t suit everyone and can be hard to follow over time. Many people experience limitations in social settings, when eating out, or in everyday situations where carbohydrate-rich foods are common. For people with certain medical conditions or who use medicines that affect blood glucose regulation, strict low-carb diets may involve increased risks and should therefore only be undertaken in consultation with a healthcare professional.

Physical activity and LCHF

Regular physical activity is an important part of a healthy lifestyle, regardless of diet. Being physically active supports better health and can help with weight loss, especially with maintaining a lower weight over time. When you’re in an energy deficit, strength training is particularly valuable because it can help preserve muscle mass during weight loss.

With a low-carbohydrate diet, high-intensity training may feel more challenging because access to carbohydrates as a rapid fuel source is limited. How this affects training varies between individuals and depends on factors such as training background, intensity and how strict the diet is.

That’s why it’s important to find a form of physical activity that fits your body, your everyday life and your circumstances, and that you can do regularly over time.

Low-carb diets and medical treatment

When using modern weight-loss medicines, a high-fat diet can increase the risk of gastrointestinal side effects. For that reason, at Yazen we generally do not recommend combining LCHF with these medicines. At the same time, we value each person’s ability to make their own choices and find an eating pattern that works in daily life. We therefore encourage you to speak with your Yazen team before making major dietary changes, so any adjustments can be made based on your personal needs and circumstances.

Summary

On a low-carbohydrate diet (LCHF), carbohydrate intake is restricted and a larger share of energy comes mainly from fat, but also from protein. For some people, this can increase satiety, reduce energy intake and support weight loss, especially in the short term. People with type 2 diabetes may, in some cases, find that a low-carbohydrate diet makes blood glucose control easier.

At the same time, effects vary between individuals and LCHF is not superior to other ways of reducing energy intake. It can be difficult to sustain over time, may increase the risk of nutrient shortfalls, and isn’t suitable for everyone – particularly with certain medical conditions or medicines.

The most sustainable route to weight loss is therefore an individualised and flexible approach, where diet, physical activity and lifestyle changes are tailored to personal needs and circumstances.

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