In the world of macronutrients, carbs get a bad rap, thanks to the interest in low-carb diets like the Atkins, Whole30, and ever-so-popular keto diet. Diets like these limit your carb intake in order to promote weight loss, and sometimes lead to other health benefits, like curbed cravings and lower blood-sugar levels.
While most of these diets try to keep your daily carb count very low, you can still have your plate of pasta here and there. The zero-carb diet, on the other hand, is even more restrictive. Its goal is to near-completely cut carbs out of your diet, meaning everything from starchy vegetables to baked goods like cookies are almost always off limits.
Like most low-carb diets, chances are you will see weight loss on the zero-carb diet, which is also called the no-carb diet. But it’s so restrictive that some experts think the diet is more risky for your health than anything. Carbs aren’t the villain they’re made out to be, and in fact, they play a major role in brain function and help keep your nervous system functioning properly, among a ton of other benefits.
Here’s everything you need to know about the zero-carb diet and its risks, according to registered dietitians.
What exactly is a zero-carb diet?
Generally, a zero-carb diet involves cutting most carb-containing foods from your diet as possible (namely digestible carbs). The name is a bit of a misnomer, since you are technically eating *some* carbs.
“This is the most extreme version of other well-known carb-cutting diets such as the Atkins diet and keto,” says Tamsin Jordan, a registered dietitian in New York specializing in women’s health. Most people limit their intake of carbs found in foods like non-starchy vegetables, nuts and seeds, and cheese.
When cutting down on carbs, some people choose to limit digestible carbs in particular. Digestible carbs are those that can be completely broken down into sugar (or glucose). Refined grains, pasta, and starchy vegetables like corn are just a few examples of foods that pack digestible carbs.
“Consuming excessive amounts of highly processed, digestible carbs will lead to sharp fluctuations in blood sugar, causing wild swings in energy, mood, and focus,” says Jordan, who adds that these carbs are also associated with weight gain and sugar cravings.
Unlike digestible carbs, other types of carbs—fiber-rich ones specifically—are not as easily broken down, which is why they have less of an effect on your blood sugar and aid your diet by keeping you feeling fuller for longer. Jordan typically recommends focusing on the quality of carbs that you consume, rather than the quantity. Unrefined carbs are her top choice: “These contain fiber which helps to stabilize your blood sugar and provide an array of vitamins and minerals,” she says.
So how do you know how many digestible carbs are in a food? It’s not an exact science, but a good way to get an estimate is to look at its nutrition label and subtract dietary fiber from total carbohydrates.
How do you follow a zero-carb diet?
Generally a zero-carb diet requires you to cut out as many carb-containing foods as you can. But it doesn’t actually mean you don’t eat any carbs ever. For one, you gotta have some for your body to function properly, so skipping them altogether isn’t safe. But this diet does go pretty low on the carbs.
A typical low-carb diet would require you to keep your carb count between 100 and 150 grams per day, which would allow for a limited amount of fruit, vegetables, and healthy grains. A zero-carb diet is even more restrictive than this. There is no established limit to how many carbs you can consume, but some people try to keep it between 20 and 50 grams, which in a way can resemble a keto diet, which also requires you to strictly limit carbs.
The difference is that the keto diet is typically high in fat. “The ketogenic diet is a type of low-carb diet that is high in fat, moderate in protein and limits carbs to fewer than 50 grams, and in some cases, less than 30 grams per day,” says Jordan. “The purpose of this diet is to put your body into a state of ketosis. In this state, your body converts fatty acids from fat stores into molecules called ketones.” Your body eventually uses those for energy, burning fat instead of carbs.
Regardless of what your carb goals are, Jordan recommends lowering your carb count slowly over four to six weeks. “By tapering your carbs slowly your body has time to adjust to using a new fuel source. You will also be less likely to suffer potential side effects such as food cravings, low energy, irritability, and constipation.”
Can a zero-carb diet help you lose weight?
Yes, it’s totally possible to lose weight on zero-carb diet, and really any low-carb diet in general. Most low-carb diets, specifically keto ones, can induce rapid weight loss, per a 2020 review of low-carb diets published in the National Center for Biotechnology Information. The initial weight loss is mostly water weight, but sticking to the low-carb approach can ultimately result in fat loss too.
Stacie Ellis, a registered dietitian-nutritionist in Texas, also adds that low-carb diets can aid weight loss because they also tend to be higher in protein. “Protein makes you feel full, so it is easier for you to eat less food and still feel satisfied. In addition, protein requires more energy (calories) to break down, so individuals who do diets that are higher in protein will end up burning more calories just by eating,” says Ellis.
But sorry, pasta lovers. Though you may experience weight loss, something like the zero-carb diet really isn’t sustainable if you’re a natural carb lover, says Ellis. “My recommendation for the carb lovers who want to try this diet is to be a little lenient with their macro distribution and avoid doing extreme low-carb diets like the zero-carb diet because it’s unlikely you’ll be able to keep that diet up as a lifestyle,” she says.
Instead, Ellis says, “Try a low-carbohydrate diet that still allows a decent amount of carbohydrates, like getting 30-40 percent of [your] diet from carbohydrates. As long as you increase your protein to around 30 percent of your calories you will still lose weight.”
Are there any other health benefits to a zero-carb diet?
There are some benefits associated with limiting carb intake in general. Restricting carbs could be used as an effective approach to improve cardiovascular risk and features of Metabolic Syndrome, a cluster of symptoms associated with an increased risk of conditions like stroke and diabetes, found a 2008 study published in the Lipids Journal.
It’s also been shown that a low-carb diet can improve blood sugar levels in people who are obese and improve or even reverse type 2 diabetes, per another study published in the Journal of Nutrition and Metabolism.
Ellis also points out that a low-carb diet may help overweight people lower their risk of chronic diseases, though she says this is more so associated with the actual weight loss. “Individuals have lowered their blood sugars and triglycerides, and increased their HDL cholesterol. These improvements, however, may be due to the overall weight loss and not due to the diet itself, and [they] would [likely] see the same benefits if they tried other diets that helped them lose weight.”
Are there any side effects to a zero-carb diet?
Experts say there are plenty. Since carbs are the body’s main source of energy, eliminating carbs can also lead to low energy, fatigue, poor mental function and nutrient deficiency, says Jordan, who doesn’t recommend the type of extreme carb restrictions required of the zero-carb diet. “While there are health benefits associated with moderating your carbohydrate intake, a zero-carb diet is not something that I would recommend, unless medically indicated,” she adds.
Ellis says that a low-carb diet isn’t the best or safest option for women of reproductive age. “Very-low-carbohydrate diets have been correlated with decreased estrogen and increased cortisol and testosterone levels in women,” she says (not a great combo if you’re looking to get pregnant, and it could cause you to lose your period, which can come with all kinds of complications). “Women of reproductive age should keep their carbohydrates at 30-40 percent of their calories, but also take note of their menstrual cycle to see if it begins to become irregular. If it does then they should increase their carbohydrates to 40-50 percent of their calories.”
People on low-carb diets should also be extremely wary of hypoglycemia, which is associated with symptoms like headache, nausea, and dizziness, Ellis also warns. “Individuals who begin having these extreme symptoms need to be careful that their blood sugars do not get too low because it can result in comas or even death in some individuals. This is especially important for individuals who have diabetes or insulin resistance.” Don’t simply chalk up your symptoms to something like the “keto flu.”
While there are some people who say they experience increased focus and clarity on keto-like diets, Ellis says this isn’t always the case. “Many individuals who are on a very-low-carbohydrate diet may feel fatigue and have a hard time concentrating. Some individuals become very irritable or cranky due to the low blood sugar.”
Another side effect that should be noted is that a low-carb diet can impact your training or workouts. “The bottom line is there is still not enough research concerning the effects of these types of diets on performance and athletes should use caution when trying any new diet in the middle of their training,” says Ellis.
Ellis also adds that some people on low-carb diets may also be more prone to injury or burnout. “Unfortunately, most people who consume [keto-like] types of diets tend to eat a large amount of inflammatory foods such as animal products. Unless individuals plan on eating a diet where their fat sources comes from foods like olive oil, avocados, and flaxseeds, they will probably end up with some degree of inflammation in their body,” she says. “With an increase in inflammation, individuals have an increased risk of sickness or even burnout and injury with training.”
Before starting any kind of diet, it’s always best to consult with your doctor to make sure it wouldn’t adversely affect your health or that it’s safe to pair with your fitness routine or training program.
What can you eat on a zero-carb diet?
If you’re going to take on a low-carb diet like the zero-carb diet, Ellis recommends packing your plate with a good source of protein and making non-starchy vegetables the base of your meal. You should also try to avoid store-bought foods as these are typically higher in carbs. “Avoid store-bought breads, cereals, granola, and even some of your protein bars. You are better off making your own so you can control how much sugar is added,” says Ellis.
Ellis also recommends eating more plant-based fats as opposed to animal-based fats to prevent an excess increase in your LDL cholesterol.
Here are some examples of foods you may typically include or steer clear of while on a no-carb diet.
Foods to avoid:
- Instant and sugary breakfast cereals
- Baked goods, including gluten-free (cookies, pastries and cakes)
- Chips and crackers
- Milk and yogurt
- Dried fruit
- Certain fresh fruit (bananas, grapes, mango, pineapple, kiwi, pear)
- Starchy vegetables (corn, potato, sweet potato/ yams, cooked beetroots)
- Low-fat and fat-free salad dressings
- Beans and legumes
- Artificial and natural sweeteners
- Fruit juices
- Regular soda
- Regular beer, cocktails, mixed drinks
Foods to include:
- Non-starchy vegetables
- Raspberries, blackberries and strawberries
- Butter and lard
- Nuts and seeds
- Dry wine and spirits
- Black tea and coffee
- Seltzer water, sugar free tonic and diet soda
Here’s what a weekday sample menu for a zero-carb diet may look like.
Breakfast: Scrambled eggs with smoked salmon and avocado
Lunch: Mixed salad greens, with lemon infused chicken breast, cherry tomatoes, olives, cucumber, olive oil dressing with sprinkle of toasted pumpkin seeds
Dinner: Roasted pork chops, Brussels sprouts and asparagus
Snacks: Swiss cheese, celery sticks
Breakfast: Turkey sausage with cooked spinach and mushrooms
Lunch: Mexican chicken lettuce taco wrap with cucumber, jalapeños, avocado, diced red onion and cilantro drizzle
Dinner: Beef meatballs with tomato sauce and zucchini noodles
Snacks: Macadamia nuts, pepperoni slices
Breakfast: Egg omelet with onions, bell peppers and grated cheddar cheese
Lunch: Spinach salad with shrimp, shaved radishes, olive oil dressing and hemp seeds
Dinner: Turkey burger, with roasted tomato, onion and zucchini skewer
Snacks: Dried seaweed, hard-boiled egg
Breakfast: Egg fried in coconut oil, tomatoes, spinach and bacon
Lunch: Pesto chicken with zucchini noodles, sunflower seeds and grated parmesan cheese
Dinner: Beef burger mixed with chopped onions, bell peppers, kale and pecans
Snacks: Cottage cheese, pickles
Breakfast: Small bowl of raspberries, blackberries and strawberries
Lunch: Tuna salad with mixed salad greens, cucumber, cherry tomatoes, red onions, olive oil, balsamic vinegar, walnuts and sprinkle of chia seeds
Dinner: Teriyaki salmon, broccoli, Swiss chard greens with aioli mayo
Snacks: Pistachios, kale chips
The bottom line: The zero-carb diet could lead to weight loss, but it isn’t a sustainable lifestyle and can even be risky for certain populations. Instead, it’s best to go for a balanced diet that includes multiple food groups and important macronutrients.
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