Low-Carbohydrate Diet: Pros, Cons, and Sample Menu
A low-carbohydrate diet limits carbohydrates, or carbs, such as those found in bread, pasta, rice, and sugary foods.
Many people follow a low- carbohydrate diet for fat loss, blood sugar control, or because they feel they function better with fewer carbs.
This article explains the benefits and downsides of a low-carbohydrate diet, foods to eat and avoid, and provides a sample low-carbohydrate diet menu.
What is a low-carbohydrate diet?
A low-carbohydrate diet restricts carbs and emphasizes protein, healthy fats, and nonstarchy vegetables.
Carbohydrates occur naturally in milk and plant-based foods, including fruits, vegetables, grains, and legumes.
Other foods have carbs — mainly in the form of sugar — added to them during the manufacturing process.
While there is no clear consensus on what defines a low-carb diet, most research defines low-carb as eating fewer than 26% of your daily calories from carbs (1).
For a healthy person who eats 2,000 calories per day, this translates to 130 grams of carbs.
For reference, the Acceptable Macronutrient Distribution Range (AMDR) set forth by the National Academy of Sciences recommends that 45–65% of your daily calories should come from carbohydrates.
This range translates to 225–325 grams of carbs per day based on a 2,000 calorie diet.
While commonly used interchangeable, a low-carb diet is less restrictive than a ketogenic — or keto — diet, which limits carbs to less than 10% of your daily calories or 20–50 grams (1).
With a keto diet, the goal is to reach nutritional ketosis, a state where your body utilizes fat and ketones as its primary fuel source rather than carbs.
A keto diet also consists of less protein and more fat than a low-carb diet.
Low-carb foods to eat
On a low-carb diet, you can load up on animal proteins, oil, and nonstarchy vegetables without hesitation since they are carb-free or contain very few carbs.
Many beverages are also carb-free.
Animal proteins and oils
Animal proteins and oils are generally carb-free.
- Meats: beef, pork, lamb, venison, and buffalo
- Poultry: chicken, duck, eggs, goose, pheasant, turkey, and quail
- Seafood: catfish, cod, clams, crabs, flounder, haddock, halibut, salmon, scallops, shrimp, tilapia, trout, and tuna
- Oils: avocado, canola, and olive oil
Because plant-based sources of protein like grains, nuts, seeds, and legumes all contain carbs, it can be difficult for a vegetarian to follow a low-carb diet and still eat enough protein.
Nonstarchy vegetables have five grams of carbs or fewer per 1/2 cup cooked or 1 cup raw.
Examples of nonstarchy vegetables include:
- bok choy
- brussels sprouts
- green onions
Carb-free beverages include water, black coffee, unsweetened tea, diet soda, and other calorie-free drinks.
Hard liquor like rum, vodka, gin, tequila, and whiskey are all carb-free. Lighter beers and wine can be relatively low in carbs.
Foods to limit or avoid
Save treats like cakes, cupcakes, ice cream, regular soda, and other sugary foods or drinks for special occasions.
These foods contain high amounts of sugar and can quickly drain your carb allowance bank account.
Other foods that can contain a significant amount of sugar that you might not expect, include ketchup, salad dressings, barbeque sauce, and peanut butter.
You should limit foods that naturally contain carbs, including fruits, starchy vegetables, grains, cereals, legumes, and milk.
But you shouldn’t completely restrict these foods since they contain important vitamins, minerals, and beneficial plant compounds called phytochemicals.
Instead, stick with portions of these foods that contain 15 grams or less per serving.
- small apple
- medium orange
- one-half banana
- 1/2 cup applesauce
- 3/4 cup blueberries
- 1 cup raspberries or strawberries
- 1/2 cup kiwi, sliced
- 1 cup watermelon, diced
- 1/3 cup cassava
- 1/2 cup corn
- 1/2 cup green peas
- 1/3 cup plantain
- 1/2 (3 ounces) potato
- 1 cup squash
Grains and cereals
- 1/4 bagel
- 1 slice bread
- 1/2 English muffin
- 1/2 hot dug or hamburber bun
- 1/4 cup granola
- 1/4 cup breakfast cereal
- 1/3 cup cooked pasta or rice
- 3 cups popcorn
- 1/3 cup baked beans, canned
- 1/2 cup cooked or canned beans (black, garbanzo, kidney, lima, navy, pinto, white)
- 1/2 cup lentils, cooked
Dairy and plant-based dairy alternatives
- 1 cup milk
- 1 cup rice, soy, and almond milk
- 2/3 cup flavored yogurt
- 1 cup plain yogurt
Sample low-carbohydrate diet menu
Here’s a one-day sample low-carbohydrate diet menu that contains less than 100 grams of carbs.
- Breakfast: 2 scrambled eggs with cooked spinach and 1 slice of avocado toast
- Snack: 3/4 cup Greek yogurt and a palmful of almonds
- Lunch: Pork loin with sauteed brussels sprouts, cherry tomatoes, and a lemon vinaigrette
- Snack: BLT lettuce wrap
- Dinner: Fish cakes with a caesar salad
This example evenly distributes the carbs throughout the day, but you can decide how you want to distribute your carb allowance based on your schedule and preferences.
A low-carb diet has several proven health benefits, especially related to fat loss and blood sugar control.
Low-carb diets are popular for fat loss because for many people, they work.
But keep in mind, if you don’t also restrict your calories, you won’t lose any weight on a low-carb diet.
The good news is that a low-carb diet tends to lower appetite, and in turn, reduce calorie intake (2).
Still, the effectiveness of a low-carb diet for fat loss compared with a low-fat diet is often overblown.
Long-term studies show no significant differences in the amount of fat loss between people who follow a low-carb diet or a low-fat diet when protein intake is controlled (3, 4).
The primary benefit that comes with a low-carb diet is that people tend to lose weight — not necessarily fat — quicker than when following a low-fat diet, but the overall weight loss between the two diets is the same in the long term (3, 4).
Despite this, many people find the quick weight loss from a low-carb diet motivating.
People who follow a low-carb diet tend to lose weight quickly due to the depletion of carbs and water from their liver and muscles.
In either case, the success of a diet for fat loss ultimately depends on your ability to follow it long-term.
Blood sugar control
To varying effects, carbs increase your blood glucose or sugar level, which stimulates the release of insulin.
Insulin is a hormone produced by your pancreas that lowers blood sugar.
Eating a low-carb diet reduces how much insulin your body needs to maintain healthy blood sugar levels.
In people with type 2 diabetes, following a low carbohydrate diet can significantly reduce the use of insulin and other medications for diabetes (5, 6).
A low carbohydrate diet also helps people with type 2 diabetes better manage their blood sugar level at rest.
If you have diabetes and take medications for your blood sugar, talk with your doctor or to a registered dietitian before starting a low carbohydrate diet since you may have to adjust your medications to avoid hypoglycemia or low blood sugar.
Here are some of the potential downsides to a low-carb diet:
It can impair exercise performance
For athletes involved in high-intensity sports like football, soccer, wrestling, basketball, and track events, following a low carbohydrate diet can impair performance (7, 8).
That’s because these sports rely on glucose to provide quick and explosive energy.
While fat can provide fuel for these sports, the process is significantly less efficient (9).
It can be low in essential nutrients
A low-carb diet can be deficient in certain vitamins and minerals, namely vitamins E, A, thiamin, B6, folate, calcium, magnesium, iron, and potassium (10).
However, you can easily get all the nutrients you need from a low-carb diet without vitamin or mineral supplements.
You can ensure you’re getting enough of the nutrients you need by eating nonstarchy vegetables of different colors, varying your protein, and still including — although limiting — dairy, grains, and legumes, depending on your daily carb allowance.
Keep in mind, though, that it can be difficult to get enough nutrients on a low-carb diet if you are vegetarian, avoid certain food groups, or follow a very low-calorie diet.
In these instances, a multivitamin and mineral supplement may be needed.
It takes planning
Following a low carbohydrate diet requires some planning.
With a limit on carbs, you must determine how you plan to track your carbs and distribute them throughout the day.
You also have to plan for holidays, celebrations, and other events centered around food.
Will the event have low-carb options or should you eat before going?
If you’re going to a gathering with friends or family, will there be low-carb options or should you bring a low-carb dish?
What about dining out?
These are all the things you’ll have to consider and prepare for with a low-carb diet.
The bottom line
A low carbohydrate diet restricts carbs to 26% of your total calories or less than 130 grams per day.
Carbs to limit on a low-carb diet include fruits, starchy vegetables, grains, legumes, and dairy.
Instead, load up on nonstarchy vegetables, meats, poultry, seafood, and oils, as these food contain negligible or zero carbs.
While a low carbohydrate diet can increase fat loss and improve blood sugars, it’s not the best diet for high-performance sports, it can be low in essential nutrients, and it requires preparation and planning to have success.