Alex Thieme Fitness - Free Resource
Everything you need to hit your fiber goal - without overhauling your diet.
Why it matters
Everyone talks about protein. Nobody talks about fiber. But here's the thing - fiber might be the single most underrated tool for fat loss, gut health, and longevity. And most people aren't getting close to enough of it.
1 Quagliani & Felt-Gunderson, American Journal of Lifestyle Medicine, 2016 (NHANES data) 2 Institute of Medicine, Dietary Reference Intakes, 2005 3 Threapleton et al., BMJ, 2013
Fiber slows digestion, keeps you fuller longer, feeds your gut microbiome, and helps move food (and waste) through your system the way it's supposed to. The research on fiber and chronic disease prevention is about as consistent as it gets in nutrition science.
For fat loss specifically, high-fiber foods take up a lot of physical space in your stomach for relatively few calories. That's a big deal when you're trying to eat in a deficit without feeling like you're starving.
Don't try to overhaul anything. Just add one high-fiber food to breakfast every single day this week - oats, chia seeds, berries, avocado toast on whole grain, whatever you'll actually eat.
That's it. One swap, one meal, seven days in a row. By the end of the week you'll have a new habit anchor, and you'll have a much better sense of which foods feel good and which ones you can build on.
Know your sources
Mark each food based on how you feel about it. Your selections will highlight meals in the next section so you can see recipes that use foods you like (or want to try). This is not an exhaustive list - it focuses on the highest-impact, most accessible sources that map directly to the recipes below.
Fiber and calorie values are approximate and may vary by variety, preparation method, and brand.
High-fiber tortillas, breads, and similar products can be useful additions, but the strongest long-term habit is fiber diversity. Aim for legumes, vegetables, fruits, seeds, and whole grains rather than relying on only a few packaged sources.
Different colored plants contain different types of fiber and phytonutrients. Red peppers, purple cabbage, orange sweet potato, dark leafy greens - the more color variety on your plate, the more diverse your fiber intake (and your gut microbiome will thank you). This is where fiber diversity matters.
On supplements: Most fiber supplements are overpriced for the benefit you get. If you see "proprietary blend" on the label, that's a red flag - it just means they don't have to disclose the exact quantity of each ingredient. If you're going to supplement, psyllium husk is a decent option.
Making it work
Recipes are organized by when you'd eat them so you can hit your fiber target from breakfast through your evening snack. Foods highlighted in yellow or green match your selections from above.
Keep it simple
The foods that make this the easiest: a sheet pan, some olive oil, and whatever's in your fridge.
This is probably the highest-value habit for increasing fiber with zero planning. Pick a protein (chicken thighs, salmon, whatever), chop up two or three vegetables - broccoli, Brussels sprouts, sweet potato, bell peppers - toss with olive oil, salt, and pepper, and roast at 425°F for 25–30 minutes. You're getting 8–12g of fiber with almost no effort, and it works as a meal prep base for two or three days.
Chia and flaxseeds in particular are easy additions - stir them into oatmeal, blend into a smoothie, or mix into Greek yogurt. One tablespoon of chia seeds adds 5g of fiber to whatever you're already making.
You don't need a new recipe. Swapping white rice for brown rice, regular pasta for whole wheat, or a flour tortilla for a corn one gets you 3–6g more fiber at that meal without changing anything else.
A cup of raspberries is 8g. A medium pear is 6g. If you're already snacking, replacing something with a piece of fruit is one of the faster ways to move the needle - and you're getting fiber, vitamins, and antioxidants in the same move.
Day in the life
You don't want to get 100% of your fiber in one meal - it's completely reasonable to hit 25g in a single sitting, but spreading it across meals makes digestion easier and keeps you consistently fuller throughout the day. Here's a rough template to work from.
Set the record straight
Three things that sound right but aren't.
Technically accurate, in the same way you can survive on very little sleep. Fiber isn't classified as an essential nutrient the way protein or water is - you won't develop a deficiency disease without it. But the research on what adequate fiber intake does over a lifetime is very clear. We're talking meaningful reductions in heart disease risk, colon cancer rates, type 2 diabetes, and all-cause mortality. "You won't die without it" is a very low bar. Optimal health is a different conversation entirely.
Supplements can fill a gap in a pinch, but they're not a substitute for whole food sources. Your gut microbiome is a community, and different fibers feed different microbes. If all your fiber is coming from one source - a psyllium husk powder, or those high-fiber tortillas loaded with inulin - you're feeding a very narrow slice of that community. Whole food fiber comes packaged with vitamins, minerals, and diverse plant compounds you don't get from a supplement.
Digestion is part of it, but it's a small part. The research on fiber is consistent - it's tied to lower rates of heart disease, type 2 diabetes, colon cancer, and all-cause mortality. The mechanism is partly direct (gut barrier integrity, blood sugar stability) and partly indirect: when fiber feeds your gut bacteria, they produce short-chain fatty acids that have downstream effects on inflammation, immunity, and metabolism. "It's good for your gut" undersells it significantly.
If you liked this guide, The Change Project is where this kind of thing lives every single day.
TCP is a group coaching community built around practical nutrition, sustainable fat loss and muscle growth, and the kind of education that sticks. Inside you'll find structured workout programming (gym and home versions), a meal planning tool, curated recipe collections, weekly AI Assistant Coach check-ins (for the Core Tier), and a library of resources that goes well beyond fiber.
The approach is practical by design - a framework built to work over the long haul, with a community doing the same work alongside you.
Join The Change Project →