Should You Eat Less Fat on Keto to Lose Weight?
Quick answer: Usually yes, but not in month one. Dietary fat on keto isn't one fixed number. It runs high while you adapt, comes down while you're losing weight so your body supplies more of the fat you burn, and goes back up when you reach maintenance. If you're past about week five, not hungry, and stalled, trimming fat is the first lever to try. Leave protein where it is.
In this article
- Why fat isn't a fixed target
- Phase one: adapting, fat high
- Phase two: losing, fat lower
- Phase three: maintaining, fat back up
- How much to cut and when
- What the research says
- KetoDick's take
- Key takeaways
Why fat isn't a fixed target
On keto, carbs are capped and protein has a target. Fat is the variable. It's the macro that rises and falls to match how hungry you are and what phase you're in. KetoDick describes fat as variable in his beginner rules: eat it to feel full at first, let it fall in the weight-loss phase, and raise it again at maintenance (video UygKGoP_BtA).
The reason is simple. When you're losing weight, you're running an energy deficit, and part of the fat you burn comes from your body. Every gram of fat you eat is a gram your body doesn't have to supply.
Phase one: adapting, fat high
In the first weeks your glycogen is gone and your body isn't yet good at running on fat. KetoDick describes the liver "up-cycling" enzymes and your cells reorganising how they use fuel, which he says takes roughly two to four weeks for thinner people and four to eight for heavier people (video NUJNFG6lLWw). Insulin is still coming down, so hunger isn't settled yet.
During this phase his advice is: limit carbs, get adequate protein, and let fat be "fairly unlimited" (from the video NUJNFG6lLWw). Telling a beginner to cut fat or calories in month one is, in his words, "kind of cruel," because they'll just feel fatigued and miserable. He also points out the timing varies with sex, age, where someone is in their cycle and more, which is why the ranges are wide.
The month-one version is in eat fat to satiety.
Phase two: losing, fat lower
Once you're adapted, hunger should start regulating itself. This is the phase where KetoDick says you can comfortably eat less without imposing restrictions, because you're no longer as hungry (video NUJNFG6lLWw).
He's specific about which calories should drop: fat, not protein. Your protein needs are based on your lean mass, which doesn't change when your appetite falls; carbs stay restricted; and fat was only ever there to fill hunger (video 8Jk5ShSUpFY). He expects fat intake to drop "rather dramatically" for many people around weeks three to six (from the video).
His back-of-envelope on why your plate doesn't need to supply it: a 100-pound person at 10% body fat carries 10 pounds of fat, which he puts at about 35,000 calories, and most people doing keto for weight loss weigh much more and carry 20–40% body fat (video NUJNFG6lLWw). Chasing a dietary fat target in this phase works against you.
Phase three: maintaining, fat back up
When you've lost what you want to lose, you no longer want a deficit, and you don't want your body pulling from fat stores you'd like to keep. KetoDick says this is when you return to something like 70–75% of calories from fat, and eat more food overall (video NUJNFG6lLWw). People who keep keto as a long-term way of eating may need to actively add fat at this point because there's no longer surplus body fat to draw on.
This is the phase where "keto is high fat" is most accurate. See the maintenance transition.
How much to cut and when
His suggestion is modest and specific (video NUJNFG6lLWw):
| Situation | What he suggests | Calories |
|---|---|---|
| Month one, hungry | Eat fat to fullness; don't restrict | n/a |
| Past week five, not hungry, frustrated with loss | Cut dietary fat by about 20 g a day | about 180 kcal |
| Same, a bit more | Cut about 30 g a day | about 270 kcal |
| Maintenance | Raise fat back to about 70–75% of calories | more food overall |
A few guardrails from the same videos:
- Don't go to bed hungry. He says he doesn't encourage anyone on keto to do that (video NUJNFG6lLWw).
- Keep protein. Cutting protein to break a stall often costs muscle; err high (video UygKGoP_BtA).
- Still hungry past week six? Look for hidden sugars and other triggers before cutting harder (video 7Aixw4uRksI).
- Track to diagnose. For beginners he suggests setting MyFitnessPal to maintain and watching carbs; a deficit tends to show up on its own (video DoSUgIr2rNo). When stalled, the log tells you where the fat is coming from.
If you're on diabetes or blood pressure medication, eating noticeably less and losing weight can change what your doses need to be. That's a reason to tell your doctor before you start cutting, not after.
What the research says
- In a metabolic-ward study of 19 adults, cutting calories from fat produced 89 ± 6 g/day of body-fat loss, against 53 ± 6 g/day for cutting the same calories from carbohydrate (Hall et al., 2015). It was short and tightly controlled, but it supports the idea that when you trim calories, trimming fat is effective.
- A meta-analysis of 24 trials (1,063 people) found that higher-protein, energy-restricted diets gave modestly more fat loss and less loss of fat-free mass (Wycherley et al., 2012). That backs the "cut fat, keep protein" order.
- The National Lipid Association's statement notes that low- and very-low-carb diets may give more short-term weight loss but are not superior for long-term weight loss (Kirkpatrick et al., 2019). Whatever you do in phase two has to be something you can keep doing.
Where he and the ward study line up: both say calories matter and fat is a sensible place to cut. Where they differ: he credits lower insulin and settled hunger for making the cut comfortable; the ward study held food intake fixed, so it can't speak to hunger at all.
KetoDick's take
His closing line in the fat video sums it up: introductory phase, fat high; weight-loss phase, cut fat back, hit your protein and keep carbs restricted; maintenance, bring dietary fat back (video NUJNFG6lLWw). He also reports that on his own log, when he tracks without restricting, he tends to run a deficit anyway, with some days near his needs and others around half.
Key takeaways
- Fat is the variable macro on keto, not a target to hit.
- Month one: eat fat to fullness. Weight-loss phase: let it come down. Maintenance: bring it back up.
- If you're past week five, not hungry, and stalled, try cutting 20–30 g of fat a day.
- Keep protein steady while you do it.
- On diabetes or blood pressure medication, tell your doctor before you change how much you eat.