• A top nutrition scientist keeps his kitchen stocked with nutritious foods.
• These include frozen spinach, lentil pasta, kimchi, and miso paste.
• Having healthy foods on hand makes it easier to whip up gut-friendly meals.

Tim Spector, a top nutrition scientist, tries to eat 30 different plants a week for his gut health — but they're not all fresh, as you might expect.

In his cookbook, "Food For Life," which is due to be published in the US and Canada on May 27, Spector calls jarred, tinned, and frozen foods the "unsung heroes of eating well," because they are affordable and nutritious.

So Spector not only stocks his fridge with whole foods that make healthy eating easy, but his pantry, freezer, and kitchen counters, too.

Here's what the epidemiologist at Kings College London and the cofounder of the nutrition company ZOE keeps in his kitchen.

Grains, tinned vegetables, and healthy flavorings in his pantry

Spector's cupboards always contain a variety of grains, such as buckwheat, spelt, pearl barley, and quinoa, which are great alternatives to rice and pasta, he wrote in the cookbook. But he keeps wholegrain and lentil pasta on hand because he's a "big pasta fan," he told Business Insider.

As many varieties of beans and pulses as he can find are also on his grocery list, because they are affordable sources of protein, fiber, and nutrients.

Spector's recipes often call for tinned and jarred vegetables, such as tomatoes, sweetcorn, olives, and artichokes, which tend to be cheaper than fresh vegetables and have a longer shelf life. But watch out for additives, Spector said, such as salt or preservatives.

Spector also keeps miso and nutritional yeast to hand as alternatives to bouillon cubes, which tend to be highly processed. He previously told BI that he tries to avoid ultra-processed foods to care for his gut health.

Vegetables, fruits, and fermented foods in his fridge

There are always plenty of vegetables, fruits, and leafy greens in Spector's fridge, as well as a small amount of "traditional cheese," he wrote, which is fermented. More research is needed to confirm the health benefits of fermented foods, but a 2022 review of studies linked them to a lower risk of type two diabetes and cardiovascular diseases.

Fermentation "experiments," such as homemade kefir and pickles, can also be found in his fridge, as well as miso and gochujang: two flavorful fermented pastes that add flavor to dishes.

Spector recommends stocking the "four Ks" in your fridge — kefir, kombucha, kimchi, and 'kraut (sauerkraut). He previously shared three tips for eating more fermented foods with BI.

Berries, soup, and soffritto in his freezer

There are yet more vegetables in Spector's freezer, including frozen cubes of spinach, peas, and mushrooms.

He also has a bag of soffritto — which is chopped vegetables (usually onions, carrots, and celery) that can be used as a base for many dishes — and frozen herbs to flavor his home-cooked meals.

Spector keeps mixed berries and fruit in the freezer too, which he uses in his go-to healthy breakfast of yogurt with toppings.

"I always try to make sure I have a nice, thick, Italian-style vegetable soup in the freezer that I can simply defrost and reheat when I'm pressed for time," he wrote. For example, the Minestrone soup recipe in his book.

Fruit and nuts on the counter

Spector keeps a fruit bowl where he can see it on his kitchen counter, as well as containers of mixed nuts. That way, if he's tempted to snack, he's more likely to go for the healthy ones that he can see.

He previously told BI about his "diversity jar" that is full of different nuts and seeds, which he keeps on hand to sprinkle on his meals and help him eat 30 plants a week.

• Tim Spector, a top nutrition scientist, said most people get enough protein but not fiber.
• He recommended people focus on increasing the amount of fiber they eat each day.
• His tips include switching meat for beans and eating different types of plant-based protein.

High-protein foods from cereal bars to pasta have taken over grocery store shelves as people try to eat more of the macronutrient. But a top nutrition scientist said fiber should be our focus.

According to the US Department of Agriculture's Dietary Guidelines for Americans for 2020 to 2025, more than half of Americans meet or exceed the minimum daily requirement for protein, which is 0.36 grams per pound of body weight.

Yet the guidelines say that more than 90% of women and 97% of men in the US don't meet the recommended intake for dietary fiber.

Tim Spector, a British epidemiologist who cofounded the nutrition company Zoe, told Business Insider that people who want to improve their diet should focus on consuming more fiber than protein. Fiber is great for gut health, can improve heart health, and can help ease constipation, among other things.

Rosa Becerra-Soberon, a registered dietitian at Top Nutrition Coaching, told BI that people should aim to have a well-balanced diet containing enough fiber and protein. Those who are particularly active and want to build or maintain lean muscle may need more protein than the amount the US government recommends, as fitness experts previously told BI.

Spector shared three tips on how to hit your protein goals while getting enough fiber.

Prioritize natural protein sources

Spector doesn't eat meat often but wrote in his cookbook, which is set to be released in the US in 2025, that he still consumes about 1 gram of protein per kilogram of his body weight per day, mostly from plants and whole foods.

While plant-based protein sources tend to contain less protein overall than meat, they contain more fiber. According to the US Department of Agriculture, 100 grams of fried tofu contains about 18 grams of protein and 4 grams of fiber.

Becerra-Soberon said that if you don't consume meat, you should make sure you get all the essential amino acids by eating grains and seeds.

Swap meat for beans and lentils

Spector wrote that replacing meat with legumes is a great way to increase your fiber intake while meeting your protein needs. Legumes such as beans and lentils are protein-heavy but higher in fiber and typically better for the environment than meat.

For example, canned chickpeas contain about 8 grams of protein per 100 grams, as well as 7 grams of dietary fiber. Chicken has 22 grams of protein per 100 grams but no fiber, according to USDA data — and it tends to be more expensive than chickpeas.

The longevity researcher Dan Buettner previously shared dietitian-approved legume recipes with BI.

Variety is key

Because plants generally contain less protein than meat, Spector wrote that he incorporates "a good mix" of plant-based protein sources into his diet throughout the day. This is because different whole foods contain different amounts of protein, so you might have to eat a "variety of nutrient-dense whole foods to take care of your protein needs," he wrote.

For example, Spector's go-to breakfast of yogurt, kefir, berries, nuts, and seeds contains about 30 grams of protein from multiple sources. He may also have butter beans with quinoa for lunch and a portion of tofu for dinner, he said.

Dr. Will Bulsiewicz, Spector's colleague at Zoe, previously shared with BI his favorite bean-chili recipe, which he eats for lunch every day. The recipe includes beans and farro, both of which are good sources of protein and fiber.

Becerra-Soberon also recommended making little additions of protein to meals throughout the day, such as by sprinkling on hemp seeds, which contain 31 grams of protein and 4 grams of fiber per 100 grams, or eating almond butter as a snack, which contains about 21 grams of protein and 10 grams of fiber per 100 grams.

• An epidemiologist and nutrition expert eats at least three fermented foods each day for gut health.
• Tim Spector shared his tips on how to incorporate fermented foods into your diet.
• These include starting small, checking food labels, and "backslopping."

You may have noticed a proliferation of kefir and kombucha in stores lately. Fermented foods are everywhere, but can be a little intimidating to people who aren't used to them.

Tim Spector, a British epidemiologist and cofounder of the nutrition company Zoe, eats at least three different types of fermented foods every day to aid his gut health.

Research on fermented foods is still developing, but, according to a 2022 review in the journal Nutrients, studies suggest that they can reduce risks of cardiovascular disease and type 2 diabetes, and increase the diversity of bacteria in the gut. The gut thrives on a varied diet, so this diversity is important for digestive and overall health.

Spector told Business Insider how he incorporates fermented foods into his diet.

Start small

"Little and often" is the best way to start adding fermented foods to your diet, Spector wrote in his cookbook "Food For Life," which is due to be published in the US in 2025.

This allows you to get used to the taste and your gut to get used to all the new bacteria.

Spector recommends adding a tablespoon of different fermented foods to your cooking — for example, kimchi in a stew for "flavor and crunch," or kefir to a soup for "creaminess and tang."

This chimes with what other experts told BI: Tanzil Miah, a dietitian specializing in gut health, said adding kimchi or sauerkraut to sandwiches or salads, and using yogurt as a sauce or marinade are easy ways to add fermented foods to what you're already eating.

Check out labels of shop-bought fermented foods

"My advice to the fermenting newcomer is to find some commercial fermented products you enjoy and slowly work up to fermenting your own," Spector wrote in "Food For Life."

When buying shop-bought fermented foods, such as kefir, kombucha, sauerkraut, or kimchi, he recommends looking for products that are:

• Low in added sugar.
• Have few/no chemical additives.
• Not pickled in vinegar, which kills live microbes.

Then make your own

When you're ready, Spector said you can expand the scope of fermented foods away from just pickles and kefir. He now makes his own homemade labneh and a fermented mushroom-and-garlic spread, for example.

Making fermented foods at home is also great for the environment and your wallet because it reduces food waste, he said.

And it's easy. "You can ferment just about any plant," he said, using only salt or honey.

BI previously reported a Michelin-star chef's techniques for making homemade kimchi, sauerkraut, and pickles.

Or, Spector said, you can make your own kefir from the dregs of a store-bought bottle with a technique called "backslopping." To backslop kefir, add a tablespoon of good-quality kefir to a bottle of full-fat milk, leave it at room temperature until it thickens, and then store in the fridge.