What Is the Role of Diet in Preventing and Managing Diabetes? (podcast)

Eating healthy, exercising, can help prevent or manage diabetes

Samantha Harris is an endocrinologist and diabetes expert at Scripps Clinic.

Dr. Samantha Harris, Endocrinology, Scripps Clinic

Eating healthy, exercising, can help prevent or manage diabetes

More than 34 million people in the US have diabetes, meaning their blood sugar is too high; another 88 million have prediabetes, a precursor to diabetes that often goes unnoticed due to the absence of symptoms, according to the Centers for Disease Control and Prevention (CDC.)

Lifestyle changes, like cleaning up your diet, can help people control their diabetes or lower the risk of developing it in the first place. 


In this episode of San Diego Health, host Susan Taylor and Samantha Harris, MD, an endocrinologist at Scripps Clinic Del Mar who specializes in diabetes and weight management, discuss the types of diabetes, their causes, and what role diet and exercise play in managing the condition.

Dr. Harris speaks in-depth about how the sugar you get from food and drinks affects the body and how a diet low in refined sugars and carbohydrates can help stave off diabetes.

Listen to the episode on how diet affects diabetes

Listen to the episode on how diet affects diabetes

Podcast highlights

What is diabetes? (0:53)

Diabetes occurs when someone’s blood sugar is too high. It can result from numerous different processes, but the two main ones are an auto-immune condition leading to low insulin production, or it can be related to metabolic syndrome, being overweight, having insulin resistance, where the body isn’t able to make enough insulin to keep up with the high blood sugars and eventually blood sugars become elevated.

What is the difference between Type 1, Type 2, and gestational diabetes? (1:22)

Type 1 diabetes is an autoimmune condition in which the body creates antibodies against the pancreas. The pancreas is an organ in the stomach that is responsible for producing insulin.

What happens with people who are no longer able to make insulin to control their blood sugars is that they require insulin injections to bring their blood sugars down.

Type 2 diabetes is related to a very complicated system with metabolic syndrome, being overweight, having other markers of inflammation that make insulin not work as well in the body. Eventually the pancreas has to make more and more insulin because of the insulin resistance and people will develop high blood sugars over time because they just can’t keep up with the process.


Gestational diabetes is diabetes that is diagnosed in pregnancy in somebody who has no history of diabetes. This is usually related to pregnancy changes as well as some impact that the fetus can have on insulin resistance.

Usually after pregnancy gestational diabetes does resolve. But women who have had gestational diabetes are at a higher risk of developing diabetes later on in life and should be followed and watched pretty closely to make sure they don’t develop it.

What are the symptoms of diabetes and prediabetes? (2:49)

Interestingly, most people don’t have symptoms when they have prediabetes or even early diabetes. And that’s because it takes a blood sugar getting pretty high before people will experience the symptoms of a high blood sugar.

The symptoms of a high blood sugar can be feeling really tired. They can be increased thirst, dry mouth, urinating more frequently, even blurry vision. There are visual changes associated with it as well. They might also notice they have recurrent infections, such as yeast infections or wounds that aren’t healing quite as well as they used to be. And that’s because the high blood sugars can affect their immune system and their healing.

Why do so many people have diabetes and prediabetes? (3:47)

That is a complicated question, but it’s likely multifactorial. A lot of it is genetics. People who are overweight or have diabetes usually have relatives who have the same types of conditions. Lifestyle also plays a factor. The fact is that we’re not as active as we probably used to be years ago, and also there are diet changes. We are relying a lot more on processed foods that are high in refined carbohydrates or sugars that drive up our blood sugars, which drives up our insulin levels and can increase our weight.

How do you manage diabetes? (4:23)

There are a lot of things that people can do to help with their diabetes. Lifestyle changes, increasing exercise, changing their eating habits, but also medications, both pills, injectable medications or insulin. Even weight loss surgery has been shown to be helpful in the treatment of diabetes. That is something I often talk about with my patients if they are a candidate for it or interested in it.

How does food and drink affect diabetes? (4:52)

What you eat and drink can directly affect your blood sugars. Let’s say, fruit juice or soda that’s high in sugar gets absorbed very quickly and it leads to rapid increases in your blood sugar. This makes your pancreas need to produce higher and higher levels of insulin in order to keep your blood sugars normal. Over time, the pancreas just can’t keep up with the amount of insulin that they have to produce. So foods that are lower in sugar and carbohydrates can often help lower this necessary insulin response and help with the treatment of diabetes.

What happens if you have too much sugar in your blood? (5:31)

High blood sugar levels over years of time can lead to complications. For example, it can affect things like your eyes, your vision, leading to blindness. It can affect kidneys, often times leading to dialysis in people with very high blood sugars for years and years. It can lead to nerve damage or increased infections. It can also lead to an increased risk of heart disease. Heart attacks and strokes are more likely in people who have diabetes. But there are some lesser known complications, effects on mood and dementia as well, and increased cancer that can result from high levels of blood sugar.

What should you do to lower the blood sugar in your body? (6:17)

To lower blood sugar levels, it really takes a multidisciplinary approach, meaning multiple different things. There’s no just one simple answer. Working on dietary changes is important and there is no one diet that you have to follow. But there are a variety of things that can help, exercise, medications, even considering surgery.

What I usually recommend is finding a doctor or health care provider that you know, that you trust, who has experience in treating diabetes and its related conditions, and really seeing them closely and often to make sure that you’re reaching the goals specific to you for your diabetes.

What foods should you have and what foods should you be avoiding? (6:59)

Overall, there are three principles to all healthy eating plans whichever one you decide to choose. Here are the three principles:

  • One, limiting processed foods, really trying to focus on whole foods as much as possible.

  • Two, increasing your intake of vegetables.

  • Three, limiting refined carbohydrates and sugar.

If somebody is coming from a typical American diet that’s high in carbohydrates, my first recommendation is usually to eliminate beverages that have sugar in them. They are unnecessary calories that drive up blood sugar, drive up insulin level, and it can be easily replaced by other non-sugar sweetened beverages. That’s usually the first change I recommend to make, in addition trying to limit things like cookies and cakes, trying to keep those focused to special occasions, trying to limit processed foods that have shelf lives of years. Generally speaking, foods that can last on your shelf for years are probably not the best for us.

More whole foods and produce will really help us, not just achieve better blood sugars but overall health.

What can people living with diabetes do to improve their health? (8:13)

I do want people to know, even though there are scary things that can happen when blood sugars are high for long periods of times, that with good control you can avoid most of these complications.

The majority of people with diabetes do not go on to develop kidney failure and blindness. It just requires some care and close work with one of your health care providers. I want you to have hope. Having diabetes is not a death sentence and there is definitely great treatment out there. Medications, lifestyle changes, just a lot of good things going on with research and one should have hope.

Lightly edited for clarity.

Watch the video on how diet affects diabetes

Watch the San Diego Health video with host Susan Taylor and Dr. Harris discussing how diet affects diabetes and the importance of eating healthy to control your blood sugar level.

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