Could an apple a day keep the extra pounds away? According to a recent study in Food Chemistry, yes, because apples contain non-digestible compounds that promote the growth of good bacteria in your gut associated with weight loss.
How it works: These compounds—fiber and polyphenols—remain undigested until they’re fermented in the colon, where they act as food for friendly bacteria and help your body outweigh the bad bacteria that thrives on junk food, says lead study author and food scientist Giuliana Noratto. This restored microbial balance appears to reduce chronic inflammation, which increases the risk of obesity, and boosts feelings of fullness to help stave off overeating.
“Obese people have an out-of-balance gut,” says Noratto. “So changing our gut bacteria via what we eat, making it similar to that of a lean person, could help prevent weight gain.” In the study, obese mice that were fed apple compounds ended up with gut bacteria similar to that of lean mice.
But what kind of apple you eat may matter. Tart Granny Smiths reign supreme: They contain the highest concentration of fiber and polyphenols compared to varieties like Gala, McIntosh, and Golden Delicious.
Need more reason embrace the fall fruit? Previous research links apples to everything from a healthier immune system to a reduced risk of stroke, diabetes, high cholesterol, and cardiovascular disease.
Aim to eat an apple a day—or up to two or three, says Noratto. As for apple pie or crisp? Sorry, those don’t count: Cooking destroys the polyphenols in apples. Try some Granny Smith slices dunked in cinnamon-spiked peanut butter instead, or paired with a sharp cheddar cheese. For a slimming winter salad with Granny Smith slices and carnival squash, try the recipe below.
Apple, Squash, Kale, and Seed Salad
1 sm carnival squash, seeded and cut into ½” wedges
¼ c plus 2 tsp olive oil
2 Tbsp minced shallot
2 Tbsp fresh lemon juice
2 tsp Dijon mustard
3 c packed shredded kale
1 lg green apple, sliced
1 ½ c cooked quinoa
¼ c each sunflower seeds and pepitas
crumbled ricotta salata cheese for serving (optional)
1. HEAT oven to 425°F. Place squash on a rimmed sheet pan with 2 tsp oil and toss well to coat. Roast until tender and golden, about 20 minutes. Set aside.
2. WHISK shallot, lemon juice, and Dijon in large bowl. Add remaining ¼ cup oil in a steady stream and whisk until incorporated. Season with kosher salt and black pepper to taste. Add kale, apples, quinoa, sunflower seeds, pepitas, and squash. Toss gently until combined. Serve topped with ricotta salata if desired.
NUTRITION (per serving) 400 cal, 10 g pro, 41 g carb, 7 g fiber, 9 g sugars, 24 g fat, 3 g sat fat, 240 mg sodium