Knowing what to eat on a low-carb diet can be confusing. After all, many so-called "sugar-free" foods are loaded with fructose, dextrose, maltose and other hidden sugars.
You must also watch out for starch, which can stall your progress. This type of carbohydrate occurs naturally in grains, root vegetables, green bananas and most types of beans. Luckily, there are plenty of delicious, healthy foods with no sugar or starch.
Except for animals foods, such as meat, fish, seafood and eggs, most foods contain small amounts of carbs, including sugars and/or starches. However, this doesn't mean they're unhealthy.
The Truth About Starchy Foods
High-carb diets are often associated with weight gain, elevated blood sugar, diabetes and other health concerns. However, the link between carbs and obesity is subject to debate, according to a February 2018 review in the BMJ Open.
Some studies suggest that eating more carbs won't necessarily cause weight gain, while others blame carbs for the obesity epidemic. Most researchers agree, however, that certain types of carbs, especially simple sugars, can increase body weight.
A low-carb diet, on the other hand, can help you slim down and improve your health. This eating pattern has been linked to fat loss, reduced blood pressure and lower cholesterol levels.
A recent study published in the Journal of Hepatology in May 2019 revealed some interesting findings on low-carb diets. Subjects who switched to a low-carb Mediterranean diet experienced significant reductions in visceral fat mass and liver fat content. The benefits were even greater for those who committed to regular exercise.
As the study authors point out, high liver fat content is a major risk factor for diabetes, metabolic disorders and heart disease. In fact, it's even more harmful than visceral fat, a type of adipose tissue that wraps around your internal organs. Cutting back on carbs may help reduce body weight, visceral fat mass and liver fat, leading to improved cardiometabolic health.
Not all carbs are created equal, though. The study published in the Journal of Hepatology, for example, was based on a diet rich in fruits, vegetables and whole grains, which are all high in carbs. Furthermore, a diet rich in carbs can be just as effective as a low-carb diet in terms of weight loss, depending on the types of carbohydrates consumed.
Carbs with a low glycemic index (GI), such as leafy greens, nonstarchy vegetables, oat bran and most fruits, have a negligible impact on blood sugar levels and may aid in diabetes management.
Starches are not necessarily harmful, but they may contribute to weight gain and increase blood sugar levels when consumed in large amounts. Health organizations worldwide recommend eating whole grains, boiled or baked potatoes, whole wheat or whole grain pasta and other high-fiber starchy foods. Dietary fiber slows sugar absorption into the bloodstream and helps prevent insulin spikes.
Foods Without Starch and Sugar
As you see, starches have their place in a healthy diet. However, if you're trying to lose weight, you might benefit from limiting carbs, including sugary and starchy foods. The good news is that you can still enjoy a varied diet and cook your favorite meals. Just remember to substitute sugar and starches with low-carb ingredients.
A no-starch diet may include unprocessed meat and fish, eggs, dairy products, green vegetables, mushrooms, rhubarb, unrefined vegetable oils, coconut oil, avocado and more. With a few exceptions, most fruits are starch-free, but they do contain quite a lot of sugar.
Read more: List of Starchy Carbs
Fructose, the sugar in honey and fruits, may contribute to metabolic syndrome, insulin resistance, oxidative stress and impaired organ function when consumed in excess, according to a March 2017 review featured in Nutrients.
This sugar also increases triglycerides and cholesterol levels, leading to a greater risk of heart disease. The reviewed recent studies indicate that it may cause inflammation in the brain and internal organs, including the heart, liver and kidneys.
These side effects, though, are due to high-fructose consumption. If you eat fruits and drink fruit juices in moderation, you have nothing to worry about.
Soft drinks and processed foods, such as energy bars, candy, breakfast cereals, granola, frozen dinners, flavored yogurt and most desserts, contain large amounts of fructose and may put your health at risk. Additionally, some people have a reduced ability to digest this sugar and may experience adverse reactions after eating foods rich in fructose.
Unprocessed Meat and Animal Products
Except for processed meat, all types of meat and poultry are carb-free. The same goes for eggs, milk, cheese, fish and seafood. Milk and its derivatives contain small amounts of carbs, but not all carbs are starches. Beware, though, that deli meats and processed dairy foods, such as fruit-flavored yogurt, may contain starch.
Pay attention to how you cook these foods. Lean ground beef, for example, has zero carbs. However, if you roll it in flour to make meatballs or meat patties, the carb count will go up. Flour, breadcrumbs, oats and other popular ingredients are high in starch.
Steam, boil, grill or roast meat and fish. Serve them with nonstarchy vegetables like celery, cucumbers, asparagus, spinach, kale, zucchini, artichokes or eggplant. Some veggies, though, may contain small amounts of sugars. Eggplant, for instance, provides 4.8 grams of carbs, including 2.8 grams of sugars and 2.5 grams of fiber per serving (one cup). If you're on a strict low-carb diet, make a list of "safe" foods to use in your recipes.
Nonstarchy Fruits and Vegetables
As mentioned earlier, not all carbs are starches. Most fruits are high in carbs and sugars, but this doesn't necessarily mean they contain starch. Plantains, bananas, dates, figs and other high-sugar fruits are typically high in starch, so it's better to avoid them while on a low-carb diet. Opt for low-sugar fruits, such as:
- Avocado: 80 calories and 0.3 grams of sugars per serving
- Strawberries: 47 calories and 7.1 grams of sugars per serving
- Blueberries: 84 calories and 9.9 grams of sugars per serving
- Cantaloupe: 46 calories and 10.5 grams of sugars per serving
- Lemon: 17 calories and 1.4 grams of sugars per serving
- Coconut meat: 283 calories and 4.9 grams of sugars per serving
When it comes to vegetables, you have a lot more options. Most veggies contain little or no sugar and can be easily incorporated into a low-carb diet. Some contain no starch at all:
- Mustard greens
- Collard greens
- Brussels sprouts
These vegetables, though, may contain carbs and sugars. Tomatoes, for example, provide 27 calories, 5.7 grams of carbs and 3.8 grams of sugars per serving (5.2 ounces). There are 52 calories, 12.2 grams of carbs and 6 grams of sugars in one cup of chopped carrots — that's one serving.
Except for meat and other animal products, most foods contain small amounts of sugars or starches. Keep a food journal and write down what you eat at every meal. Your daily carb intake will depend largely on your diet. Ketogenic diets, for instance, limit carbs to 20 to 50 grams per day, while traditional low-carb diets are less restrictive.
- BMJ Open: "Does High-Carbohydrate Intake Lead to Increased Risk of Obesity? A Systematic Review and Meta-Analysis"
- Journal of Hepatology: "The Beneficial Effects of Mediterranean Diet Over Low-Fat Diet May Be Mediated by Decreasing Hepatic Fat Content"
- MDPI: Nutrients: "Impact of High-Carbohydrate Diet on Metabolic Parameters in Patients With Type 2 Diabetes"
- Mayo Clinic: "Glycemic Index Diet: What's Behind the Claims"
- NHS: "Starchy Foods and Carbohydrates"
- Joslin Diabetes Center: "How Does Fiber Affect Blood Glucose Levels?"
- MDPI: Nutrients: "High Dietary Fructose: Direct or Indirect Dangerous Factors Disturbing Tissue and Organ Functions"
- UW Health: "Fructose-Restricted Diet"
- USDA: "Beef, Ground, 70% Lean Meat / 30% Fat, Raw"
- USDA: "Eggplant"
- USDA: "Avocado"
- USDA: "Strawberries"
- USDA: "Blueberries"
- USDA: "Cantaloupe"
- USDA: "Lemon"
- USDA: "Coconut Meat"
- American Diabetes Association: "Non-Starchy Vegetables"
- USDA: "Tomatoes"
- USDA: "Raw Carrots"
- Harvard Health Publishing: "Ketogenic Diet: Is the Ultimate Low-Carb Diet Good for You?"