What Is a Good Low-Carb Diet and How Does It Work?

Written by Mariia Roza

Written by Mariia Roza

Mariia Roza is a weight loss and fitness writer at Unimeal. She is an expert in nutrition, wellness, longevity, and sports.

on June 08, 2021

Medically reviewed by Dr. Olena Avdiievska, MD, RDN

Medically reviewed by Dr. Olena Avdiievska, MD, RDN

Dr. Olena Avdiievska is a nutritional and medical expert at Unimeal. She is an MD and RDN in Dietology and nutrition and a university professor with 76 scientific publications. 

Unimeal provides articles with trustworthy and experts-proved information. Our health content is reviewed by professional nutritionists and trainers to extract for users the most verified and medically checked data.

A low-calorie diet is one surefire way to bring your weight down safely and effortlessly. In this article, you will learn what a quality low carb diet is and what foods to eat on a LCHF diet.

Meta-analysis of multiple studies showcases that low-carb diets are more efficient for weight loss than low-calorie diets where the calorie deficit was created by decreasing the percentage of fats. But are all low-carb, high-fat (LCHF) diets efficient and safe? Are their results sustainable? What to eat on an LCHF diet to stay healthy? Are there any contradictions? Let’s find out!

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What is a good low-carb diet?

Atkins, ketogenic, paleo, and even carnivore diets are considered low-carb. However, are they all equally beneficial and safe for your health?

The thing is, even if your diet plan is as simple as “minimize carbs,” you can do it both in a healthy and unhealthy way. For example, you can have two English muffins for breakfast and spend your carbs “budget” right away. Or, you can use carbs in a smart way and have three vegetable salads along with your main courses, plus a splash of milk for your morning coffee.

A good low-carb diet should be well-balanced to provide your body with all the necessary nutrients. By balancing your meals and adding more variety to your diet, you will prevent vitamin and mineral deficiency while staying on an LCHF. By choosing high-fiber veggies for your salads, you can minimize the risks of another side effect that is quite frequent during the first weeks of a low-carb diet: Constipation. 

To get the most out of LCHF, let’s get closer to the practical side of dieting. Chech out, how you can enjoy your food and stay healthy without carbs. 

What can you eat on a low-carb diet?

A classic keto diet means that you can consume only 50 grams of net carbohydrates per day. To keep up with this rule, you will have to make high-fat and high-protein products the basics of your meals. Incorporate these products into your diet to enjoy a variety of whole foods:

Eggs

They are considered a great source of nutrients and high-quality protein.

All types of meat

Include poultry, red meat, giblets, and lard. Opt for organic meat to get the most of it, and always watch labels if you chose jerkies or other processed meats like sausages, ground beef, or canned meat.

Fish and seafood

The fatter the fish, the more omega fatty acids it will contain. You’re lucky if you live near the seaside. In this case, don’t hesitate to enjoy salmon, herring, sardines, and red snapper every day! 

When it comes to shrimp, lobsters, and crabs, remember that they might trigger an allergic reaction in some people, especially when consumed in high quantities. Make sure you tolerate seafood well before ordering a huge portion of oysters or mussels.

Fats and oils

These are the caloric basis of any high-fat diet. Butter, lard, vegetable oils: Embrace them all, and remember that fats can help you lose weight in multiple ways. Add high-fat and high-fiber olives and avocados to your diet as well to make your meals more fun and enjoyable.

Full-fat dairy

Choose heavy cream, fat types of cheese, and whole milk. Keep in mind that manufacturers often use sugar in fat-free products to improve their taste, so you have to keep your eyes on food labels while choosing dairy.

Vegetables

Vegetables do contain carbs. To stay in ketosis, opt for vegetables with low quantities of carbs and a low glycemic load. Add broccoli, tomatoes, cauliflower, eggplants, cucumbers, mushrooms, cabbage, and zucchini to your meals to keep your diet diverse and provide your body with all necessary vitamins and minerals. If you want to keep your carbs intake really low, try to minimize the amount of sweet vegetables rich in fructose, like onion and bell peppers. 

Nuts and seeds

If animal foods contain almost zero carbs, plants are usually made of carbs. For example, 100 g of almonds have nearly 22 grams of carbs. On the other hand, half of them are the fiber that won’t add to your total daily count of net carbs. All in all, being fiber-rich foods, nuts and seeds are welcomed in a low-carb diet when consumed in moderation.

Note to remember! It is not onions or peppers that makes you gain weight! So, don’t get your diet to extremes, and don’t stigmatize healthy whole plant foods like 90%-water vegetables that happened to be slightly sweet!

Fruits

Depriving yourself of desserts might feel complicated at first, but don’t forget that you have fruits and berries to munch on when you crave something sweet. Choose fruits and berries rich in fiber but low in fructose, like strawberries, apricots, oranges, and grapefruits.

Dry wine

If you don’t want to refrain from your little guilty pleasure – a glass of dry red wine after a hard day in the office, you don’t have to. Even though alcohol can slow down your weight loss, ketogenic diets allow you to treat yourself once in a while with a bit of dry wine as it contains only two grams of carbs per 100 ml.

Stevia

Suppose you want to sweeten something up while on a low-carb diet. You can use stevia extract. It doesn’t affect your insulin response as it contains zero carbs and zero calories. 

Products to limit while on an LCHF diet

Fifty grams of carbs per day is not that much! To keep up with this number, you will have to eliminate entirely or at least minimize these products.

• Sweets and sugar
• Honey, agave syrup, fructose
• Bread and grains
• Sweet fruits with a high glycemic index (raisins, dates, bananas, mangoes)
• Starchy vegetables (potatoes, sweet potatoes, corn)
• Pasta
• Cereal
• Beer
• Fat-free dressings and dairy
• Beans and legumes

How does a low-carb diet work?

First of all, let’s see how your body reacts to carbohydrates and what happens with insulin, one of the satiety hormones when you eat something sweet.

How is insulin produced?

When you eat carbs, they broke into sugars. After that, sugars absorb into the blood, which increases glucose levels. If your pancreas works well, it produces the proper amount of insulin. Insulin is essential to metabolize carbs by promoting glucose absorption in the liver, fat cells, and skeletal muscles.

If the pancreas produces too much insulin, it prevents fat burning. It is also responsible for storing nutrients in fat cells. This means that even if you had a nutrient-rich, dense meal, your body won’t receive it and would still think that you’re deprived of food. The perceived shortage of nutrients in the blood would lead to hunger.

This is how people gain weight because of a too high insulin response. Large amounts of carbs make their pancreas produce too much insulin, making it harder for the body to use fat reserves and simultaneously simplifying fat storage. 

Don’t think that insulin is something terrible! On the contrary, it’s an essential peptide hormone in our bodies that regulates food metabolism and helps our bodies to get energy from food. However, its sensitivity might lead to weight gain.

What is ketosis?

Low-carb diets are targeted at using other ways of food metabolism for energy. For example, our bodies have a special mechanism for transforming fatty food directly into energy. It is called dietary ketosis⁴Paoli A., Rubini A., Volek J. S., et al. (2013, June 26). Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition. DOI:10.1038/ejcn.2013.116. So, how does it work?

When you lower your carbs intake, fewer carbs are broken into sugars. This means that fewer sugars are absorbed into the blood, and you have lower blood glucose levels. As a result, your pancreas produces less insulin. Less insulin means that the release of fatty acids from your fat cells is simplified, and you can burn fat more efficiently. 

Why does this happen? Because your body still needs energy and glucose, and as you don’t give it glucose, it has to produce it by itself. So, glucogenesis starts. Glucogenesis⁵Veldhorst M. A. B., Westerterp-Plantenga M. S., Westerterp K. R. (2009, September). Gluconeogenesis and energy expenditure after a high-protein, carbohydrate-free diet. The American Journal of Clinical Nutrition. DOI:10.3945/ajcn.2009.27834 is the process of creating glucose from fatty acids in your liver. During glucogenesis, your liver produces ketone bodies.

After several days on a low-carb diet, when all the reserves of glucose are spent, ketone bodies, produced by the liver from the fatty acids, are oxidized into energy and become the primary energy source for your body, brain⁶White H., Venkatesh B. (2011, April). Clinical review: ketones and brain injury. Critical Care. DOI:10.1186/cc10020, heart, and other organs.

What are other mechanisms of LCHF diets?

As you don’t consume carbohydrates anymore, you don’t have insulin spikes that make you feel hungry. In addition to that, as you don’t consume fast energy sources, and energy from fatty acids is released slower, you feel satiated for longer. 

Another thing that affects your hunger/satiety balance is that you consume more protein known⁷Sumithran P., Prendergast L. A., Delbridge E., et al. (2013, July). Ketosis and appetite-mediating nutrients and hormones after weight loss. European Journal of Clinical Nutrition. DOI:10.1038/ejcn.2013.90 to be more satiating than other macronutrients. What’s more, the ghrelin (hunger hormone) levels turned out to be significantly lower⁸Volek J. S., Phinney S. D., Forsythe C. E., et al. (2009, April). Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids. DOI:10.1007/s11745-008-3274-2 among those who used an LCHF diet to lose weight. 

Some studies⁹Ebbeling C. B., Feldman H. A., Klein G. L., et al. (2018, November 14). Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance: randomized trial. BMJ. DOI:10.1136/bmj.k4583 also claim that low-carb diets don’t alter your metabolism rate as much as low-fat diets, making the weight loss results more sustainable in the long run. 

Contradictions of LCHF diets

Low-carb diets are not for everyone. If you have any doubts or acute health conditions, make sure to consult your doctor before starting an LCHF diet!

According to scientists, several conditions are incompatible with low-carb diets. Primarily, these are liver and kidney acute diseases. Diabetes patients should also consult their health providers when switching to an LCHF diet, as they will need to adapt their insulin doses.

Health benefits of the low carb diet

Even though many people nowadays chose a low-carb diet to lose weight faster and easier, we should notice that LCHF diets have multiple benefits for health as well. These are just some of them.

Cardiovascular disease and cholesterol levels. Today, there is strong evidence¹⁰Brehm B. J., Seeley R. J., Daniels S. R., et al. (2003, April). A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. The Journal of Clinical Endocrinology and Metabolism. DOI:10.1210/jc.2002-021480 that low-carb diets can improve cholesterol and lipid profiles and increase the size¹¹Volek J. S., Sharman M. J., Forsythe C. E. (2005, June). Modification of lipoproteins by very low-carbohydrate diets. The Journal of Nutrition. DOI:10.1093/jn/135.6.1339 of the LDL cholesterol particles. These changes lead to lower risks of cardiovascular diseases. 

Type 2 diabetes. A very low-carb diet can help with diabetes symptoms, and there is considerable scientific evidence proving this fact. LCHF diets decrease glucose levels and insulin sensitivity which make them highly beneficial for type 2 diabetes patients.

Epilepsy. The ketogenic diet was first introduced to treat epilepsy in the 1920s, and it still might be used to decrease child epilepsy symptoms. A very low-carb diet is known¹⁶Kessler S. K., Neal E. G., Camfield C. S., et al. (2011, September). Dietary therapies for epilepsy: future research. Epilepsy and Behavior. DOI:10.1016/j.yebeh.2011.02.018 to reduce seizures by 30-40% and decrease the use of medications. 

Acne. Studies¹⁷Cordain L. (2005, June). Implications for the role of diet in acne. Seminars in Cutaneous Medicine and Surgery. DOI:10.1016/j.sder.2005.04.002 show that a high-glycemic load might stimulate acne in the skin. As low-carb diets, as a rule, have a low-glycemic load, it can improve the state of acne. Moreover, some trials show that adopting a low-carb diet can significantly help treat acne vulgaris.

Decrease sugar cravings. Some studies state that sugar can lead to addiction²⁰Wiss D. A., Avena N., Rada P. (2018, November 7). Sugar Addiction: From Evolution to Revolution. Frontiers in Psychiatry. DOI:10.3389/fpsyt.2018.00545 which is why some keto newbies feel the withdrawal symptoms when they start a low-carb diet. What’s beneficial about an LCFH diet is that it helps deal with sugar addiction and decreases sugar cravings in the long run.

There are also studies stating that a low-carb diet can help with migraines²¹Di Lorenzo C., Coppola G., Sirianni G., et al. (2014, August 25). Migraine improvement during short-lasting ketogenesis: a proof-of-concept study. European Journal of Neurology. DOI:10.1111/ene.12550, balancing fertility hormones²²M. McGrice, J. Porter (2017, February 27). The Effect of Low Carbohydrate Diets on Fertility Hormones and Outcomes in Overweight and Obese Women: A Systematic Review Nutrients DOI:10.3390/nu9030204, and treating irritable bowel syndrome²³Austin G. L., Dalton C. B., Hu Y., et al. (2009, March 10). A Very Low-carbohydrate Diet Improves Symptoms and Quality of Life in Diarrhea-Predominant Irritable Bowel Syndrome. Clinical Gastroenterology and Hepatology. DOI:10.1016/j.cgh.2009.02.023. However, some additional research should be conducted to get strong scientific evidence of these benefits.

Possible side effects of an LCHF diet

One of the most frequent effects of carbohydrate withdrawal²⁴Harvey C., Schofield G. M., Zinn C., et al. (2019, June). Effects of different levels of carbohydrate restriction on mood achievement of nutritional ketosis, and symptoms of carbohydrate withdrawal in healthy adults: A randomized clinical trial. Nutrition. DOI:10.1016/j.nutx.2019.100005 is a so-called “keto flu.” Its symptoms include migraines, low mood, leg cramps, bad breath, and constipation. These conditions might be explained by the fact that carbs increase water retention in the body, and when you stop consuming them, your body rapidly loses liquids. One of the ways to prevent keto flu is drinking enough water and increasing your salt consumption. 

Even though some people notice a significant decrease in physical performance,various²⁵Wilson J. M., Lowery R. P., Roberts M. D., et al. (2020, December). Effects of Ketogenic Dieting on Body Composition, Strength, Power, and Hormonal Profiles in Resistance Training Men. Journal of Strenght and Conditioning Research. DOI:10.1519/jsc.0000000000001935 studies²⁶Greene D. A., Varley B. J., Hartwig T. B., et al. (2018, December). A Low-Carbohydrate Ketogenic Diet Reduces Body Mass Without Compromising Performance in Powerlifting and Olympic Weightlifting Athletes. Journal of Strenght and Conditioning Research. DOI:10.1519/jsc.0000000000002904 state that this effect is short-term. The performance will rise again after some time on ketosis. 

Why are you gaining weight on a low-carb diet?

Studies show that you should lose weight faster on a low-carb diet, but you don’t. So, what can be a problem? Let’s check out some of the frequent mistakes people make on LCHF diets. 

You eat too many nuts

First of all, nuts still contain a lot of carbs, and you can easily go beyond your 50 grams per day limit. 

The second reason why nuts might make you gain weight is that they’re extremely calorie-dense. 

And the third hazardous peculiarity of nuts is that they’re tasty snacks, and if you’re prone to mindless eating, you can end up consuming a massive pack of them without even noticing it.

You consume too many calories

Even if you decrease your insulin production, calories will still matter. It is true that while on a ketogenic diet, most people don’t have to count calories as they feel satiety faster and rarely have hunger urges triggered by insulin spikes. However, if you’re prone to overeating and consume much more calories than your total daily calories needs, you will gain weight. 

To deal with this problem, pay more attention to how much you eat and try to make three square meals during the day instead of snacking all day round.

You have a water retention

People tend to consume more salt while on a low-carb diet, which might lead to higher water retention in the body. This means that even when you lose fat, your weight can still be on the same level or even become higher. Unfortunately, water retention looks precisely the same as fat storage. To get a better visual effect, try to decrease your salt consumption a little and think of cosmetic treatments to drain water.

Summing up: Advantages and disadvantages of a low carb diet

Low-carb diets have proven their efficiency for weight loss and have multiple health benefits. Moreover, studies show that by following an LCHF diet, people have more chances to maintain their new weight because of ketogenic diets’ lower metabolic adaptation effect. Another advantage of LCHF diets is that they’re easier to follow. You have strict rules to obey and don’t have to count calories.

Low-carb diets have some disadvantages as well. First of all, they’re not for everyone. For example, people with kidney or liver conditions should consult their health providers before starting a low-carb diet. Pregnant women and those who breastfeed should also refrain from LCHF.

Another disadvantage of low-carb diets is that they might be hard to follow by some people, and they’re rarely sustainable for life. Just imagine never having your favorite dessert anymore! Can you agree to that?

All in all, well-balanced low-carb diets are legit and can help you lose weight faster and maintain your new weight for longer.