4 Risks of Following the Zero-Carb Diet, According to a Dietitian

Low-carb diets have been around for decades, but in true dieting fashion, they've been taken to the extreme lately. Enter: The Zero-Carb Diet. If we look back on our history of fad diets, we should have seen this one coming.

Decades ago, fat was the culprit. We gobbled up anything and everything that was low-fat or even better, no fat, with little to no regard for calories, carbs or the quality of the food we were eating. Then it was low-carb, and then avoiding all sugar, and now, the goal of this diet is to avoid all carbs, period.

Again, if we look back, we can be pretty certain how this one will end, too.

The Zero-Carb Diet, also referred to as the No-Carb Diet, aims to eliminate as many carbohydrates from your diet as possible for the purpose of losing weight. For context, the Atkins diet allows 20 to 100 grams of ‌net‌ carbs (total carbs minus fiber), depending on your weight-loss goals, per the official Atkins website. Atkins and other low-carb diets aim to keep your intake low, but still allow some carbohydrates to be consumed, like a limited amount of fruit, starchy vegetables, whole-grains, etc.

The goal of the Zero-Carb or No-Carb Diet is to eat as close to zero grams of carbohydrates per day as possible. In fact, one rendition of this diet is the Carnivore Diet, which promotes avoiding all plant foods and eating only animal-sourced foods (e.g., meat, eggs, seafood, etc.), because most (not all) contain no carbohydrates.

This may sound a bit like the keto diet and while there are similarities, the keto diet has established macronutrient recommendations. There are variations of the diet but generally, carbohydrates are limited to 5 to 10 percent of your total calories, according to the Harvard T.H. Chan School of Public Health.

So, if you eat 2,000 calories per day, you are allowed 25 to 50 grams of carbs per day. Fat should make up 70 to 80 percent of the diet and protein, 10 to 20 percent. Note: This doesn't make keto "healthier," we're just noting the differences.

When you hear of low-carb diets, you likely imagine cutting out all sweets, bread, pasta and maybe even fruit and starchy vegetables. But the truth is — save meat, oils, eggs — most foods contain some carbohydrates.

For instance, a cup of cauliflower has 5 grams of carbohydrates, per the USDA. And an ounce of almonds provides 6 grams of carbohydrates, according to the USDA, while a serving of avocado has almost 6 grams of carbs, per the USDA.

Eliminating or severely limiting foods like these with a proven track record in supporting our health for the sole goal of eating zero grams of carbohydrates is dangerous and unhealthy.

Some Zero-Carb Diet followers do eat nuts, seeds, coconut, avocados and non-starchy vegetables. Because there are no set macronutrient guidelines, there's flexibility for the dieter to interpret and follow at their own discretion.

• ‌Meat and poultry:‌ Beef, pork, turkey, chicken, bison, lamb and venison
• ‌Some animal by-products:‌ Eggs, butter, lard and cheese
• ‌Seafood:‌ Tuna, salmon, shrimp, scallops, sardines, mussels
• ‌Non-starchy veggies:‌ Zucchini, cauliflower, kale, broccoli, Brussels sprouts, mushrooms
• ‌Fruits high in fat:‌ Avocado and coconut
• ‌Nuts and seeds:‌ Almonds, pistachios, walnuts, chia seeds, pine nuts and flaxseed
• ‌Calorie-free beverages:‌ Water, coffee, tea

• ‌Whole grains:‌ Brown rice, quinoa, oatmeal, whole-wheat bread, whole-wheat pasta
• ‌Fruit:‌ Apples, oranges, raspberries, banana, mango, pineapple
• ‌Beans and legumes:‌ Black beans, lentils, chickpeas, hummus,
• ‌Starchy vegetables:‌ Potatoes, sweet potatoes, corn, carrots and peas
• ‌Dairy:‌ Milk, yogurt, ice cream
• ‌Refined grains:‌ Pasta, white bread, white rice, muffins, pretzels‌,‌ bagels
• ‌Dessert, sweets and baked goods:‌ Doughnuts, chocolate, candy, ice cream, pie, cake,
• ‌Alcohol:‌ Wine, sprits, beer

To sum it up in one word — no. Will you lose weight? Yes, probably, but losing weight and being thin doesn't equal health.

First, the recommended guidelines by leading health organizations agree that carbohydrates should make up 45 to 65 percent of your total calorie intake per day, per the Mayo Clinic. So, if you're eating 2,000 calories per day, you should be taking in 225 to 325 grams of carbohydrates.

Then there are the foods you're cutting out or severely limiting while on the Zero-Carb Diet like whole grains, vegetables, fruit and legumes. These foods are the major sources of fiber in our diet and the many health benefits of fiber from reducing cardiovascular disease to supporting gut health are proven, as outlined in an April 2013 review paper published in the journal ‌Nutrients‌. These foods also contain phytochemicals, antioxidants, vitamins and minerals that you cannot find in meat, butter or eggs.

Lastly, you're filling your plate with animal proteins and products with no regard for fat, saturated fat, sodium or protein. Highly processed meats and cheeses can be high in sodium and, aside from poultry and seafood, most of these foods are high in saturated fat.

National guidelines limit saturated fat intake to 10 percent of your total calorie intake and 7 percent is ideal for further reducing risk of heart disease, according to the U.S. National Library of Medicine. Using the same 2,000-calorie diet, this would mean consuming no more than 16 to 22 grams of saturated fat per day.

The only quasi-benefit is the one we mentioned before — you may lose weight — but that doesn't mean you'll be healthy. There are a number of risks with following this diet, including:

1. ‌Nutrient deficiencies:‌ By skipping out or vastly limiting your intake of beans and legumes, whole grains, fruit and starchy vegetables, you are putting yourself at significant risk for nutritional deficiencies. You would be missing out on important vitamins, minerals, antioxidants, phytochemcials, fiber, probiotics and prebiotics.
2. ‌Poor gut health:‌ By cutting out major sources of probiotics, prebiotics and fiber, you are putting your gut health at a disadvantage. Fiber is necessary for a healthy gut, normal digestion and bowel movements. Probiotics and prebiotics are what help our guts flourish and stay healthy, along with other potential benefits like supporting our immune system, weight and mental health.
3. ‌Hurt, not help your heart :‌ The diet is focused on eating primarily animal-based proteins and products, with no limit for the amount of saturated fat that should be consumed. Replacing whole grains, fruit and vegetables, with foods high in saturated fat can raise your lipid levels, which is troublesome for your heart, as stated by the American Heart Association. There are decades of research showing the harmful effects of too much saturated fat in our diet.
4. ‌Develop an eating disorder:‌ Dieting and disordered eating are risk factors for developing an eating disorder, according to both the Academy of Nutrition and Dietetics and the National Eating Disorders Collaboration.