Kate Middleton eats this heart-healthy 'superfood' for breakfast each day

Kate Middleton's health journey has been in focus since she announced her battle with cancer.

Middleton, 43, reportedly enjoys a fruit- and vegetable-heavy diet, the U.K. publication wrote. 

But for breakfast, she consistently chooses "slow-burn energy oats."

Oats provide lasting energy and are a great source of fiber, protein, vitamins, minerals and antioxidants, according to Healthline.

The food can also help prevent type 2 diabetes and lower blood sugar and cholesterol levels due to the presence of beta glucan, a type of soluble dietary fiber.

Eighty percent of the protein found in oats is avenalin, which is similar to the protein found in lentils, peas, chickpeas, beans, peanuts and other legumes.

"Since oats are a higher-carbohydrate breakfast, for some people, they don't feel as full or crave snacks soon after, so I suggest adding in a scoop or two of natural nut butter, a handful of walnuts or almonds, or a couple of eggs on top for savory oatmeal," she told Fox News Digital.

"And an absolute must is adding some ground flaxseeds or hemp seeds right into the oatmeal to bulk up the omega 3 good fat content," she added.

"You aren't giving yourself an opportunity to veer off your plan," she noted.

DeCicco warned that some studies have found oat-containing products could have trace amounts of a popular chemical called glyphosate, which has been linked to metabolic disorders and liver disease.

To avoid glyphosate and maximize health benefits, she recommends choosing oats containing a USDA Organic certified label.