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Top 7 myths and facts about low-carb eating

Updated: Apr 7, 2021

Research now shows breast cancer thrivers who adopt an eating pattern to reduce diabetes live longer. It may explain why breast cancer survivors with diabetes have a higher risk of recurrence. Have you maybe considered eating low-carb?

There’s a lot of online buzz about low-carb eating lately. Some say it's amazing. Others warn that it can increase your risk of heart disease, and going too low carb may even increase your risk of dying.

So, what is it?

Let me help you figure out what exactly a low-carb diet is and whether it’s something you should consider… or not. Here are 7 myths and facts about low-carb eating.

You're invited to join our new private nutrition group for thrivers on Facebook for a limited time!

Myths and facts about low carb eating and pasta
Myths and facts about low carb eating

What are “carbs” (and are they bad)?

No, carbs aren’t inherently bad (more on this below).

Carb is short for carbohydrate. Carbs are one of the three main macronutrients in the diet. Macro, as in large, means they’re large components of your diet. Just like protein and fat, carbs give us the energy we need for optimal health. Most foods contain two if not all three of these essential macronutrients.

Carbs are usually discussed in the context of diabetes. Diabetes is a metabolic disorder that causes issues with blood glucose levels and insulin, a hormone produced in the pancreas. There are different types of diabetes. It’s a common, yet serious condition that often requires lifelong management.

Let’s start with the key hormone insulin. The pancreas makes this vital hormone that helps your muscles, fat, and liver use blood glucose for energy. We get blood glucose, also called blood sugar, from the foods we eat and from the liver.

Typically, blood glucose levels rise after eating and then the pancreas releases enough insulin into the blood to help move glucose into our cells. If muscle, fat, and liver cells don’t respond to insulin, glucose sticks around in the blood. When cells stop responding to insulin, the body has a tough time using blood sugar for energy. Over time, this insulin resistance can lead to prediabetes and eventually type 2 diabetes.

Consistently having high blood glucose levels damages the body. Among other screening and diagnostic tests for diabetes, a blood test can measure how much insulin is in your blood. If insulin levels are high, it may indicate insulin resistance or type 2 diabetes.

Possible benefits for thrivers

The benefits of cancer survivors living longer with an eating pattern for diabetes may be related to insulin resistance. (For more on this, see my previous post, Why eating to prevent diabetes also helps breast cancer survivors live longer. Insulin resistance is a condition like prediabetes that is a precursor for a diabetes diagnosis. Insulin resistance and prediabetes occur when the body doesn’t respond to insulin properly.

In women with newly diagnosed new hormone receptor-positive, HER2/neu-negative breast cancer, increasing insulin resistance was associated with a higher Oncotype DX™ (ODX) recurrence score. This genetic test is used to to help doctors understand a person’s recurrence risk and if they benefit from chemotherapy.

However, although Black women are disproportionately affected by insulin resistance and have worse outcomes, they did not have higher Oncotype DX™ (ODX) recurrence scores. This may be due to other health disparities yet to be interpreted.

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Fun foods can be part of low carb eating
Fun foods can be part of low carb eating

Top 7 myths and facts about low-carb eating

Fact 1

Low-carb diets may help some people better manage their diabetes, high blood sugar, metabolic syndrome, and heart disease. They may also help improve cholesterol and blood lipids, too. Low-carb diets may do these (slightly) better than low-fat diets.


These may occur not specifically from eating fewer carbs, but rather because of the quality of food choices when eating a low-carb diet. Studies show the overall quality of a food or diet is more important than focusing on just one nutrient, like carbs.

Fact 2

Low-carb diets may have a slight advantage for weight loss when compared to low-fat diets.


Studies find that after 12 months, the benefits are not that large. It’s very difficult to stick to a diet for the long-term, so finding an eating pattern that works for you is key.

Consult a dietitian who will explore all possibilities with you (I'm now doing teleheath for patient's convenience).

Fact 3

Low-carb may help you—at least for a short time. It will take experimentation to find the right way to eat for your genes, metabolism, and lifestyle.


Be careful when you restrict any major food group, like carbs, for example. This is because you may be restricting key vitamins or minerals. This can lead to deficiencies and long-term concerns like bone loss, gut problems, and chronic diseases.

Because low-carb diets are restrictive and may not provide all necessary nutrients, this diet isn’t recommended for adolescents or pregnant or breastfeeding women.

Fact 4

Low-carb diets are healthy. Low carb diets emphasize eating more of the other two macronutrients: protein and fat. It also includes nonstarchy vegetables.


Most of the research on low-carb diets is short-term, so we don’t know all the possible health effects for eating like this over the course of many months or years.

Both too high and too low carb have health risks. Moderation may be the way to go. In a study with 15,000 adults published in The Lancet Public Health, people who ate a moderate amount of carbs, or a little over half their calories from carbohydrates, lived longer than those who ate high- and low-carbohydrate diets.

Additionally, low carb usually includes more meat, poultry, fish and eggs. Eating too much animal food you may increase your risk of heart disease and is not the recommended way to eat for breast cancer thrivers and other cancers. But choosing more plant-based proteins, such as whole grains, beans, and nuts, rather than animal proteins, lead to lower death rates among low-carb eaters.

Fact 5

How low the carbs go is universally agreed.


A low carb diet isn’t specifically defined. A typical low-carb diet would recommend no more than 50-150 grams of carbs per day (that’s 200-600 calories per day). This is in contrast with the Dietary Guidelines for Americans which recommends about 225 grams (900 calories) each day from carbs.

Fact 6

Eating too much sugar or eating any one food causes diabetes.


Your overall food choices have a long-term effect on your health. The key is choosing a variety of foods from each food group: proteins, vegetables, fruits, whole grains, nuts, seeds, legumes, and healthy fats.

Selecting foods that help keep your blood glucose in target range can help you feel better and help prevent other health complications. Keep in mind each person’s body responds slightly differently to specific foods and various portions. We all have different needs.

Fact 7

You'll feel better on a low carb diet.


Not necessarily. If you make drastic changes to your diet you may experience headaches, fatigue, muscle cramps, skin rashes, and digestive upsets. Keep an eye out for these and consult an expert if you experience them.

If you restrict carbs too much you can change your body’s metabolism and put it into ketosis. This is because your body uses sugar as its main energy source, so when you don’t get a minimum amount of carbs, your body’s metabolism changes to start using fat as its energy source.

If you end up craving carbs, experiencing gut issues or other bothersome symptoms, or simply don’t enjoy eating anymore, a low-carb diet may not be the best one for you.

Carbs are part of a healthy diet.

Remember, there are healthy and not-so-healthy low-carb foods. When replacing carbs with proteins and fats, be sure to mostly choose ones that have quality proteins and fats and a lot of essential vitamins and minerals.

When it comes to fats, focus on foods rich in omega-3s and unsaturated fats and choose fewer fats that are saturated and hydrogenated.

As for proteins, for breast cancer thrivers it’s best to get them from plant sources such as nuts and beans, and less from red meats like pork and beef.

Nutrition is only one piece of a healthy lifestyle. For those who are insulin resistant or have prediabetes, resistance training and aerobic exercise can help lower insulin resistance. Muscles use blood glucose for energy. Plus, exercise can help your body use insulin more efficiently. These factors work together to help improve your overall health.

Carbs can definitely be part of a healthy diet. They’re found in many foods that are full of other nutrients like essential vitamins and minerals. Just like fats and proteins, carbs can also be found in nutrient-poor low-quality foods.

But going low carb or how many carbs are best for you, needs to be determined while working with a dietitian. Nutrition is not one-size-fits-all, especially after a breast cancer diagnosis.

Reaching health goals is something I specialize in. If you’re considering changing your diet, book an appointment with me to see if my service can help you.

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