Still Hungry on Keto While Losing Weight? Add Fiber Before You Add Fat
A Facebook Live from the last day of February 2020, recorded on my way out the door to kickboxing. It was for the people doing the New Year's reboot in the group, about two months in. It opens with five minutes on the coronavirus, then gets to the real subject: the "I need more fat" mistake.
In this recording
- [0:03] A coronavirus preparedness aside, as I understood it that week (see "Watching this in 2026" below).
- [5:18] The complaint I hear all the time: still hungry, hitting the calorie target, so "I must need more fat". That's true in maintenance, I said, and almost never true during weight loss. The usual answer is fiber.
- [6:01] Where to find it: the structural, stemmy parts of plants. Broccoli and asparagus stems, cauliflower, the stems on baby spinach.
- [6:51] A tablespoon of butter or a shot of olive oil has almost no fullness and a lot of calories. A cup of broccoli is the opposite.
- [7:23] When people on the reboot send me their logs, the meat, fish, cheese and oils are there. The vegetables aren't.
- [7:59] If nothing else, psyllium husk capsules. You need several to get a real dose, and they swell in water overnight.
- [9:28] How much? I said 30 g a day, and 40 or 50 wouldn't hurt.
- [10:34] An electrolyte powder I'd been trying, with 1,000 mg of potassium (as potassium citrate) per 16-ounce glass. I said I bought it myself and nobody sponsored me. I'm not naming it here.
- [11:08] Signs you may need more potassium: cramps, low energy, headaches, and hard exercise coming up.
- [12:19] A gripe about "trace minerals" on labels: if they won't name them, ignore them.
- [13:45] I open a psyllium capsule on camera. It's just ground-up plant material that soaks up a lot of water.
- [15:11] My own progress since New Year's: visibly slimmer. Men lose faster, I'm strict, I box, I live alone and coaching is part of my job, so don't compare yourself to me. The goals I named: back under 200 lb, under 20% body fat, ideally nearer 15% (live GUQX2721).
- [17:24] A mention of coaching, left out here.
The claim worth unpacking: fiber fills you up
My core claim was that in the weight-loss phase, hunger is usually a fiber problem, not a fat problem. The evidence pages support the direction:
- Reviewing trials, about 14 g a day of added fiber was associated with about 10% lower energy intake and about 1.9 kg of weight loss over roughly 3.8 months (Howarth et al., 2001).
- The type of fiber matters. In randomized trials, more viscous fibers reduced appetite in 59% of comparisons against 14% for less viscous ones, and acute energy intake in 69% against 30% (Wanders et al., 2011).
My number holds up too. The US reference intake is 14 g per 1,000 kcal, which is 25 g a day for women aged 19–50, 21 g for women over 50, and 38 and 30 g for men (IOM, 2005). In a large review of observational studies, the biggest reductions in mortality and disease risk showed up at 25–29 g a day (Reynolds et al., 2019). So "30, maybe more" is in the right range.
Where my explanation and the evidence pages part company is the insulin part. At [6:01] I said insoluble fiber won't cause an insulin response the way some soluble fiber does. The fiber evidence page doesn't test that. What it does show is that soluble fiber (2–10 g a day) gave small falls in total and LDL cholesterol (Brown et al., 1999), and that the viscous types did better on appetite. So I wouldn't steer anyone away from soluble fiber on that basis.
Then vs now
A year earlier I said fiber "is not going to help you lose weight", it's just very good for your health (live IEGQ4170). In this live, fiber is my first answer to hunger in the weight-loss phase. That's a real change, and the 2020 version is closer to the Howarth and Wanders findings above. Two weeks before this one, the week-six live made the same point, ranking fiber with protein for fullness (live HCIB5705). The habit goes back to 2017, when I told people to spend their carbs on vegetables (video 1vyxuWlxT5M).
Watching this in 2026
The first five minutes are a snapshot of what one non-expert believed about a new virus on 29 February 2020: masks, packages, how worried to be. I'm not going to repeat it or defend it here. It wasn't health advice then and it isn't now. For anything about infectious disease, go to your doctor or your public-health authority, not a keto video.
What holds up is the butter line at [6:51]. "Does a shot of olive oil fill you up?" is still the quickest way I know to explain why adding fat doesn't fix hunger when you're trying to lose weight.
Who should check with a doctor first
- Medications: fiber supplements taken at the same time as medication can interfere with absorption. I made that point myself in an earlier live (live IEGQ4170). Ask your pharmacist about timing.
- Potassium: if you have kidney disease or take blood-pressure medication, talk to your doctor before adding a potassium supplement or salt substitute. The WHO suggests potassium-containing salt substitutes except for people at risk of high potassium (WHO fact sheet).
Key points
- Hungry during weight loss? Look at your fiber before you add fat. Fat adds calories without much fullness.
- Stems and leafy greens are the cheapest source. Psyllium capsules are the fallback.
- Around 25–30 g a day is where the reference intakes and the big review land.
- Potassium before hard exercise if you get cramps, headaches or low energy, but ask your doctor first if you have kidney or blood-pressure issues.
- Don't compare your rate of loss to mine. Men, strict plans and full-time attention all speed things up.
Related
- Guide: hunger and fat loss · fiber · too much fat? · potassium and magnesium · medications
- Blog: always hungry on keto · soluble vs insoluble fiber · eat less fat to lose weight · keto constipation · light salt · comparing weight loss
- Videos: week six of the reboot · 2019 basics and the protein rule · spend your carbs on vegetables · eating too much fat