If you had to choose between eating a nice, tender fillet of salmon or ... umm, anchovies ... which would you choose?

You'd probably choose the salmon, right?

But Shakuntala Thilsted, the winner of this year's World Food Prize, would like people to know that small fish — like anchovies, sardines and herring — are an all around superfood. They can fight malnutrition, prevent stunting and promote good cognitive development in children. And they're awesome for pregnant women.

What's surprising is that the world didn't actually have much scientific evidence of small fish and its nutritional benefits — until Thilsted came along. It's the reason why she's being recognized for the award. She studied the impact of small fish on diets in countries like Bangladesh and Cambodia. And she came up with cheap and sustainable ways for low-income families to grow them in their backyards.

Thanks to her, said U.S. Secretary of State Antony Blinken in a statement for the World Food Prize, "millions of low-income families across many countries ... are eating small fish regularly, dried and fresh, in everything from chutneys to porridge, giving kids and breastfeeding mothers key nutrients that will protect children for a lifetime."

Thilsted, based in Penang, Malaysia, is the global lead for nutrition and public health at WorldFish, an organization that works to advance aquatic food systems. Descended from a family of Indian Hindu migrants to Trinidad and Tobago, she is the first woman of Asian descent to receive the prize.

In our conversation, we discuss the perks of having your own personal pond, the benefits of fish powder and how much fish you should eat a day. This interview has been edited for length and clarity.

I find it a bit surprising that we didn't already know that fish was a nutritious food. I feel like everyone knows it's good for you.

In many cultures, fish is considered healthy and good brain food. But the value of fish in terms of nutrition has been limited. If you talk to people, they talk about fish and other aquatic foods as just being a protein food. But protein is just one nutrient.

There are multiple nutrients in fish — micronutrients, vitamins, minerals and essential fatty acids. These nutrients, including Vitamin B12, are very important for cognition, growth and development in children and also for keeping their mothers well-nourished.

The idea of fish having this value for improving nutrition and health in women and children was not really known until I started [researching and studying the nutritional value] of small fish in Bangladesh about 20 years ago, then later on in Cambodia and countries in Asia and Africa.

I thought pregnant women were supposed to go easy on eating fish.

Many national dietary guidelines recommend pregnant women continue to eat fish during pregnancy. However, it is recommended that pregnant and lactating women reduce — not eliminate — certain types of large ocean/marine fish species such as large fish like tuna, salmon or trout due to possible heavy metal concentrates.

Small fish have a much shorter lifespan than large fish and therefore have less chance of concentrating heavy metal contaminants — making them a safer option for pregnant women and lactating mothers. The fact they are farmed in backyard ponds reduces the chance of contaminants even further.

For those where fish and aquatic foods are part of local diets, culture and food production, especially in low- and middle-income countries, the crucial nutrients in aquatic foods for growth and health make them an important addition to diets of mothers and children in the first 1,000 days of life.

You're a big fan of small fish. Why is that?

In many parts of Asia and Africa, common small fish species have a big impact on human health and the cognitive development of children. But we must also think beyond just fish to other aquatic foods such as seaweeds, which are also very nutritious.

Small, native fish are more accessible to the poor. They do not fetch a high price like carp species at market, which means they can be grown in the backyard pond, harvested by women and cooked for daily meals.

So, should we switch to just eating small fish?

I would not recommend all people eat small fish over large as both are extremely nutritious. Producing and consuming diverse fish is good for human health and the environment.

After you found out that small fish was a superfood, how did you get people actually eating it?

The first step was, of course, having the supply. I worked in Bangladesh with pond polyculture, finding ways for people to produce small fish together with large fish in ponds. At that time, people would only stock their ponds with large fish — and you would remove the ponds of the native small fish beforehand.

And in your method, you'd just have people leave those small native fish in.

Yes.

When you talk about these ponds, I'm picturing the aquatic equivalent of my grandmother's vegetable garden in her backyard. Are you saying that in Bangladesh everyone has their own personal pond in which to grow fish?

In Bangladesh, over four million households have ponds — they're called homestead ponds. That's due to the way people build homes in the country. Because the land is flat and low, people must elevate the land on which their home is built with extra soil. To do that, they dig up earth from the ground to use for the house. That becomes a depression that is used as a pond. But this isn't unique to Bangladesh. I work in India, Zambia and Malawi, where people have homestead ponds.

Do you have your own pond in Penang?

I don't in Penang as I live on the 18th floor! [ha ha!] But while I worked and lived in Cambodia, I had a backyard pond where I cultivated many small fish and had a vegetable garden on the surrounding banks. All essential for diverse homemade meals.

Have you gotten any pushback from people when you tell them to grow small fish in their ponds?

Well, maybe just in the beginning. One season of pond polyculture takes about seven to eight months. If you can get people onto the first season and have them see a higher production of fish at the end, it means they get more income and more fish in their kitchen. So it's a win-win situation.

So, the proof is in the pond.

Yes. And it's better for the environment. The past method of growing large fish would mean that you had to clean the pond before you stock the large fish [people thought it would help the large fish grow better]. Cleaning the pond was by using pesticides, which was the most expensive part of the production system. So, you greatly reduce the production cost.

What's the most nutritious way to eat small fish?

You eat the whole fish, including the head and bones. Cook it whole or you can convert the fish into a fish powder, which is extremely powerful because you are removing the moisture content and concentrating the nutrients by a factor of four. In Malawi, Zambia, Sierra Leone, where I work, families have mortars and pestles in their kitchens that they use to roast the fish and pound it. And when you have fish powder, you can keep it for months.

You can sprinkle fish powder on porridge and it's a very easy way to add nutrients to a child's diet. You can also make a fish chutney. One tablespoon given to a pregnant or lactating woman would give quite a lot of micronutrients.

What does the fish powder taste like?

It depends on how you cook it. Think of it as an ingredient in the pantry kept in a container brought out to add flavor and a health boost in food. Depending on where you are, it will be prepared differently to fit local tastes and desires. It is often mixed with spices. For example, in Bangladesh with turmeric.

You've spent decades working in research and academia. Did you face any gender discrimination in your career?

Sometimes, some of the ideas that I would come up with would be brushed off. Maybe it was because of gender, but maybe it was because I was challenging old ideas and old norms. They repelled my ideas around pond polyculture.

They told me that if you have small fish together with big fish, then the growth of the big fish would be hampered by the small fish. And I said, no. That diversity can be a strength and sustain the systems. That idea was against the science of the day. But through my research, I was able to get people to come around.

Is there any particular fish that you enjoy eating most?

No. I guess this goes back to my childhood, with my grandmother ruling over the kitchen. There was great attention paid to the diversity and seasonality of foods that we eat. When I'm in Bangladesh, I eat some of the small fish cooked like a curry together with vegetables. Here in Malaysia, there's such a wide variety. Just tonight I had clams, squids, all different kinds of aquatic foods.

That's a lot of fish. Should I be eating that much a day?

We've calculated how much should be on the plate, and we've used the portion size of 25 grams of raw fish for children and 50 grams of fish for women.

What's the portion size of say, a fillet of fish that I could order at a restaurant?

Like, 200 grams [about 7 ounces].

Wow, that's a lot!

Not if you're eating a balanced plate of diverse, nutritious foods.

What are you going to do with your $250,000 prize?

I have not at all thought about that! Well, one of my pet projects has been focusing on the education of young children in the countries where I have worked. So maybe that.

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