Do You Need to Exercise on Keto? And Is Keto Really a High-Fat Diet?
In this video
One of my first lives, 31 days into keto, answering forum questions with the dog chewing a bone in the background. I said up front I was practising broadcasting for a business podcast. I also said I had no channel and no plans for one.
- [0:00] Disclaimer first: not a dietitian or medical professional. "Ideas, suggestions, take them or leave them" (from the video).
- [1:30] "Do I need to exercise?" depends on your goals and your time. Prioritise.
- [2:00] If meal prep and groceries are handled and the food is on track, then add exercise.
- [2:30] Keto is "a way of eating, not necessarily a way of life" (from the video). It has no special exercise prescription.
- [3:00] Only people carrying a lot more muscle than usual are likely to need carbs around training.
- [4:00] Exercise is good for you, but it isn't the lever for weight loss.
- [4:30] Every medical intervention carries risk. That's how I framed keto.
- [5:00] Some people raise heart, liver and kidney-stone concerns with long-term keto, and genetics matter.
- [5:30] People who call it "WOE" expect keto for life. I wasn't sure about very low carb for life.
- [6:30] Background insulin falls with weight loss, so some people may be able to go back to more normal eating.
- [7:30] Nutrition: broccoli and lettuce aren't "empty carbs," and cream-and-butter coffee is missing most of the vitamin profile.
- [8:30] At a 1,300–1,500 kcal target, a 500 kcal bulletproof coffee leaves two-thirds of your calories for everything else.
- [10:00] I said I promote nothing, sell nothing and have no commercial interest.
- [10:30] Keto flu: not influenza. Either under-adaptation, or salt and minerals that disappear along with processed food.
- [12:00] My numbers, and the point of the whole live: keto isn't really high fat.
The claim worth unpacking: "slightly higher fat and almost no carbs"
This is the best arithmetic on the channel, and I'd still lead with it. Here are the numbers as I gave them (video uXzscHudgt0):
- Before keto: about 2,000 kcal a day, with 250–300 g of carbs. At 4 kcal per gram, that's 1,000–1,200 kcal from carbs. Protein and fat split the rest, roughly 400–600 kcal each.
- Day 31: appetite down so far that I was eating 1,000–1,200 kcal a day at about 70% fat. 70% of 1,000 kcal is 700 kcal of fat.
- The difference: 700 against 500–600 before is about 100 kcal more fat. At 9 kcal per gram, that's 10–11 g.
So the "high-fat diet" was mostly the old diet minus the carbs. Fat went up a spoonful. Total intake fell by about 800–1,000 kcal, because the hunger went with the carbs. The percentage looks high because the total shrank.
That's the version of keto I'd hand anyone who's scared of the fat. You aren't being told to eat a stick of butter. You're being told to stop eating the bread, and let fat make up the small gap. More in is keto a high-fat diet? and how much fat.
One thing to watch, looking back: by my own numbers, day 31 was below the 1,300–1,500 kcal target I gave in the same video. If your appetite drops that far, protein is the part not to lose. In energy-restricted trials, higher-protein diets lost modestly more fat and less fat-free mass (Wycherley et al., 2012).
The line that holds up: nutrition beyond fat bombs
The bulletproof-coffee point at [8:30] is just as sound. A third of a small calorie budget spent on cream and butter leaves less room for everything else. The evidence on low-carb menus agrees there's a real gap:
- In menu modelling of four diet plans, including Atkins for Life, none met the reference intake for all 27 micronutrients from food (Calton, 2010).
- In the A TO Z trial, women on Atkins had shifted toward inadequate thiamine, folate, vitamin C, iron and magnesium by eight weeks (Gardner et al., 2010).
"Spend your carbs on vegetables" got its own video the next day (video 1vyxuWlxT5M), and it's already here in this live. See nutrient deficiencies on low carb and bulletproof coffee.
Then vs now
Exercise. The position held. Weight loss made in the kitchen, exercise for health: that was the stock answer in the exercise video uploaded the same day (video f119qGyJ7AY). The trials agree that exercise and protein work together for muscle, which is a different goal from the scale. In 49 trials, protein supplementation increased resistance-training gains in fat-free mass and strength (Morton et al., 2018). See exercise benefits beyond weight loss.
Fat. This live is the start of the "eat less fat" thread. Later in August 2017 it became "stop pushing the fats" (video NUJNFG6lLWw), and by 2018 fat was the variable you raise and lower by phase (video UygKGoP_BtA).
Money. In this live I said I sell nothing and wasn't planning a diet channel (video uXzscHudgt0). That didn't last as stated. The channel happened. By January 2018 I was taking donations and an Amazon wishlist (video -dHjt_Bpruk), and by 2019 I was offering paid coaching (video hHFu6L-yedE). I'd rather say that here than leave the 2017 line standing alone.
Long-term keto and your doctor
I named heart, liver and kidney-stone concerns without detail. On the heart side, the National Lipid Association found low- and very-low-carb diets lower triglycerides and raise HDL, with a variable effect on LDL (Kirkpatrick et al., 2019). Across 13 long trials, LDL-C came out higher on very-low-carb ketogenic diets than on low-fat (Bueno et al., 2013). If you have heart disease, a family history of it, or you take cholesterol medication, ask your doctor for a lipid panel before you start and again once you've been at it a while. If you've had kidney stones, ask your doctor before going very low carb. See cholesterol and kidney stones.
Key points
- Exercise is good for health, but food is the lever for weight loss. Get the kitchen right first.
- Keto has no special exercise rules, except for unusually muscular athletes who may need carbs around training.
- By my own day-31 numbers, keto meant about 10 g more fat a day and about 800–1,000 fewer calories.
- Fat bombs and bulletproof coffee use up calories that vegetables and protein need.
- Low-carb menus can fall short on several micronutrients (Calton 2010, Gardner 2010).
- Heart risk or kidney stones: lipids and a doctor's view before going long-term.
Related
- Guide: exercise in maintenance · carbs around workouts · side effects · keto flu
- Blog: weight loss is made in the kitchen · tired during workouts · is keto sustainable? · lifestyle vs diet · fat bombs
- Videos: do I need to exercise? · dosing carbs for hard workouts · what is bulletproof coffee? · eating too much fat