What’s in Your Fridge, Doc? The Real-Life Diet of an Expert on Nutrition and Cancer

Medical oncologist Neil Iyengar

Medical oncologist Neil Iyengar studies the relationship between diet, metabolism, and cancer. He says that maintaining good nutritional habits that can be sustained may benefit more people than a highly restrictive diet.

A growing body of research shows that good nutrition can play a significant role in the prevention of cancer. But how do we turn the best of intentions into smart decisions when standing in front of the fridge or eyeing snacks at the office?

Neil Iyengar is a medical oncologist who treats people with breast cancer and a leading researcher on the relationship between diet, metabolism, and cancer. He says that research conducted at MSK and elsewhere shows that “what’s really important to good health isn’t trying to stick to a specific diet, which usually can’t be sustained. Instead, it’s important to practice good dietary habits overall and maintain a sense of moderation.”

He credits his research into diet and exercise with making him more mindful of how he eats, from curbing his sweet tooth to coping with meals on the go.

No Sugar, No Cancer? A Look at the Evidence
A lot has been written about the relationship between sugar and cancer. Most of it is wrong.

If we looked in your fridge, what would we find?

My family eats a wide diversity of foods. Research shows that for the vast majority of people, the food you eat can deliver all the nutrients you need, without supplements or other additions. However, there are definitely staples we always have on hand:


Fruits and vegetables are a great source of fiber, especially when they are whole and minimally processed. Fiber is great for slowing our digestion and metabolism. It helps us maintain healthy levels of insulin and cholesterol, and it improves the diversity of bacteria in our gut. This is important for health overall. Preliminary data suggest that fiber may help in cancer prevention as well as improve the body’s response to some cancer therapies.

Sparkling Water

I’m part of a generation that was raised drinking soda, and I drank a lot of soda until I got to medical school and really saw what it does to the body. I understand the love of a fizzy drink, but now it’s flavored sparking water for me. I’m much healthier without all that sugar.

Subscription Meal Plans

There are some great subscription meal plans out there that deliver healthy prepared meals on a weekly basis. After researching several, I chose a plant-based subscription program because of the health benefits and because I sampled and enjoyed the foods in this plan. When I have a busy day, I bring a prepared meal to work and toss it in the microwave instead of ordering in.

I know there can be sticker shock. It’s discouraging that a fast food burger costs a buck and healthy food seems expensive. But my family compared the cost of some services against takeout and grocery shopping and found some good healthy options that wind up costing about the same.

I understand the love of a fizzy drink, but now it's flavored sparking water for me.
Neil M. Iyengar medical oncologist

Healthy Snacks

We buy them at the beginning of the month and make sure they’re healthy, like almonds or unsweetened granola. I take them with me to the office so I don’t feel deprived and am still being mindful of what I’m eating.

What made you more mindful of what you eat?

During medical school, I started thinking about all the sugar I was consuming, in my coffee and even in foods like some yogurts and granola bars. Over a few years, I retrained my taste buds to care less about sweets. It wasn’t a quick fix. It was just being more aware. When you have a piece of chocolate cake after a hard day at work, that can be fine. But be aware that it’s a special event, not something you do every day. Eventually, I started getting less and less pleasure from sweet foods. At this point, I enjoy a dessert now and then, but I genuinely prefer savory to sweet.

Inspiration can come from many places too. I care for people with breast cancer. I had a patient who had many health problems in addition to breast cancer. One day she came in and I found that her tests for cholesterol and several other health markers had dramatically improved after years of switching between various medications. I asked her if she was doing anything different. She told me she had cut out meat and went on a plant-based diet.

I had been contemplating removing meat from my own diet for quite some time, but this was the push I needed to finally make the change. As a researcher, I knew the data and how beneficial it can be to consume a plant-centric diet. However, it wasn’t until I was inspired by the personal story of my patient that I decided to give it a try. We all live in an environment in which obesity and weight gain are everyday occurrences, and seeing others break free of this environment can be very helpful.

This is why I believe that teamwork is important. Many studies support the notion that living a healthy lifestyle is much easier when you surround yourself with other people doing the same — be it your family, friends, or coworkers. At the same time, one type of diet will not work for everyone. It’s important that individuals find good habits that work for them and they can sustain. Speaking to a nutritionist and your doctor can help identify dietary and lifestyle patterns that could be specifically helpful to you. Individualizing dietary recommendations is also a very active area of research. Finding a group that is supportive of your goals can be the key to long-lasting behavioral change.

What is your research revealing about the relationship between nutrition and cancer?

The Skinny on Fat and Cancer Risk
Scientists are learning how obesity — having too much body fat — increases your chance of developing cancer.
Learn more

Much of it involves the connection between fat, inflammation, and cancer. We’re all aware of the obesity epidemic in America. I think some people have misconceptions about fat. Fat is dynamic — it doesn’t just sit there. Excess fat can turn into dysfunctional tissue and become inflamed. In trying to heal the inflammation, the body produces more cells, just like healing a wound. But these new cells aren’t needed, and that increases the chance that they can grow out of control, which is cancer. Fat can also disrupt the signals that control insulin, which can damage DNA and cause cancer. Accumulation of disruptive fat can occur through poor diet, lack of exercise, and even just aging.

Is a person safe if they are not obese?

No. Research is finding that this dynamic can happen even in people who are in the normal weight range and have an average body mass index. It turns out that the composition of the body is important too. A person can be a normal weight but still have too much fat, which is another reason to concentrate not just on weight but on making sure your lifestyle is healthy.