The #1 Nutrient to Help You Lose Weight

As a dietitian, I see plenty of expensive products in the marketplace that claim they’re the answer for weight loss, whether it’s a new weight loss tea, “detox” supplements or some rare fruit that burns fat. In reality, it’s not unique superfoods or supplements that will lead to weight loss—it’s eating more fiber that can help.

Fiber is the indigestible component of plant-based foods, like fruits and veggies, legumes, whole grains and certain seeds, like chia seeds, and is the No. 1 nutrient you should be eating more of if you’re trying to lose weight. Even if you aren’t trying to lose weight, you likely should eat more for better health, regardless. Here’s how it works, plus what you can do to reap the weight-loss benefits of eating more fiber.

How Fiber Supports Weight Loss

It’s Not Digested

Fiber doesn’t contain any calories, and we don’t fully digest it. It’s in the skin and flesh of plant foods and adds filling volume to our meals. Fiber also slows down the rate of digestion, which is why we feel satisfied for longer after a high-fiber meal and less inclined to reach for a snack soon after. So, essentially, the filling nature of fiber-rich foods can help you eat fewer calories overall, which can help you lose weight.

It Enhances Short-Chain Fatty Acid Production

You’ve heard of pre-and probiotics, but postbiotics are the new darling of the gut world. Postbiotics are produced from the fermentation of fiber in the gut and the type that may help you with weight loss are called short-chain fatty acids (SCFA). Increasing SCFA production from fiber fermentation may increase the levels of leptin in the body—the hormone that regulates our appetite and tells us we’re full. SCFAs can also decrease inflammation in the body, which can make it easier for your body to lose weight.

It Makes Less Room for Other Foods

When you have a diet rich in dietary fiber, aka fiber from foods that you eat, not supplements, you may not have room for other foods that don’t support your weight loss goals. Foods high in fiber are also typically high in water, which can help keep you full.

How Much Do You Need to Eat to Lose Weight?

You should get 14 grams of fiber per 1,000 calories in your diet. So, women should aim for 25 grams of fiber per day and men should try for at least 38 grams daily. Everyone’s needs will be slightly different depending on how many calories you eat each day.

This is a healthy amount to aim for, but an even better measure is to pay attention to your individual hunger and fullness cues. If you are hungry an hour after a meal, think about how to pump it up with more fiber next time. Could you have switched from white bread to whole-wheat? Chosen fruit as a side? Topped your salad with beans and nuts instead of croutons? Protein and fat also play a role in fullness, so adding a serving of each to your meals along with plenty of fiber is important.

When increasing fiber-rich foods in your diet, you’ll want to start slowly and add one or two plant foods each day until you reach your fiber goals. And since fiber absorbs water, be sure to drink more water as you increase your fiber consumption to prevent cramping or constipation.

Ways to Eat More Fiber

Incorporating more fiber into your meals is easier than you think. Add some berries to your morning bowl of cereal, prepare overnight oats, try a breakfast muffin or make a morning smoothie.

Swap out white bread for whole-wheat bread when you make sandwiches.

Add a whole grain (like brown rice or whole-wheat pasta) to your lunch or dinner, use zucchini noodles instead of pasta or try cauliflower “rice” as a substitute for rice. Add beans to a salad or try a plant-based burger instead of meat for a Meatless Monday.

Snacking is also a great way to get more fiber in your day. Meal-prep some higher-in-fiber snacks to make it easy to eat more fiber.

If a meal plan is what you’re looking for, our high-fiber meal plans show you how to piece together a full day (or week!) of healthy high-fiber meals and snacks:

The Bottom Line

Fiber is the number one nutrient that you should increase in your diet if weight loss is what you want. It keeps you full, helps to produce SCFA to reduce inflammation, and increasing fiber-rich foods in your diet may decrease your intake of foods that are not helping you reach your goals. Remember to increase your fiber intake slowly and drink plenty of water to prevent digestive issues. Try incorporating some delicious new higher-fiber recipes with breakfast, dinner, lunch or snacks.