Dear Mark: Fish Oil Study, 1500 Calories, Breaking a Plateau, and Bulletproof Coffee vs IF

For today’s edition of Dear Mark, I’m answering four questions. First up is from Milad, who wonders about the recent research seeming to show that fish has little to no effect on heart disease. Is it right? Are we wasting money and enduring fish burps for nothing? Next, how low is too low? If a person’s eating 1500 calories and feeling completely satisfied, should he preemptively increase calories before bad things start happening? After that, I give a couple tips for breaking through a weight loss plateau. And last, how does Bulletproof coffee “fasting” compare with actual intermittent fasting? Is it a better alternative?

Let’s go:

Hey Mark,

Long time reader and fan so I’ll keep this short:

Fish Oil Not So Perfect After All

That, which you may have already seen. Observational study?



Thanks, Milad.  They only examined patients who either had heart disease or had a confluence of risk factors for it, like hypertension, high cholesterol, and/or type 2 diabetes. In other words, these were people who were already being treated for heart disease. They were on statins, blood thinners, beta blockers. They were on special diets. They were receiving advice and careful monitoring from health professionals.

A more recent paper found that in subjects who weren’t taking any lipid-lowering medication, fish oil supplementation improved biomarkers related to heart disease risk. These biomarkers were extensive and indicative of actual physiological mechanisms, mind you. They weren’t just the usual “LDL and HDL” measurements. Patients taking fish oil had lower “very low-density lipoprotein cholesterol, intermediate-density lipoprotein cholesterol, remnant lipoproteins, triglycerides, low-density lipoprotein cholesterol, AtherOx levels, collagen-induced platelet aggregation, thrombin-induced platelet-fibrin clot strength, and shear elasticity.”

I suspect fish oil has very different effects depending on your baseline treatment status. Fish oil works for heart disease, in part, by reducing hypertension, lowering blood lipids and inflammation, and thinning the blood. If you’re already taking drugs that reduce inflammation and cholesterol (statins), hypertension (beta blockers), and thin the blood (warfarin), fish oil may have reduced or even negative effects. The benefit of going with fish oil, or at least working with your doc to try fish oil before going with the meds, is that you avoid the considerable side effects that accompany statins.

And even if fish oil and omega-3s in general are useless for heart disease patients (they are not), they’re still beneficial in other situations. A few examples:

Obviously, the best way to obtain omega-3s and many other protective nutrients is through seafood consumption, but a good quality fish oil is a worthy substitute when you can’t get good fish.

Hi Mark,

I love the research you put into your posts; it is far more reassuring trusting your advice when you back it with research and science.

Now, I used to be overweight, but I have recently switched over to a cleaner diet – based on your concepts, thank you! – but I eat a ton of vegetables with every meal and my daily caloric intake averages about 1500 calories because of it (I am a 5’9″ 190 pound guy). So my problem is that I always feel full but my logic tells me I should be eating more. Is this healthy?


At 5’9″ and 190, you probably still have some excess weight to lose (unless you’re a powerlifter type), and that partially explains why you feel good on such a low calorie intake. You’re consuming ample amounts of animal fat calories drawn directly from your body. And since you’re eating tons of vegetables, you’re probably getting all the micronutrients you need. This contributes to your satiety levels and will stave off many of the health issues normally associated with low calorie diets (which usually turn out to be low nutrient diets).

You’re okay as long as you feel okay. You say you “feel full.” Do you feel good? Do you have enough energy, or do you feel like you’re lagging halfway through the day? How’s your sleep? How’s your performance in the gym (or wherever you get your activity)? Do you feel mentally sharp? Are you in a generally good mood, or at least as good a mood as you were before going Primal?

Then you’re okay.

Just be vigilant and stay aware of how you’re feeling before it gets out of hand. You’re obviously thinking about this stuff pretty deeply, so I’m not really worried about you. Keep me posted, though!

Hey Mark,

I have been eating primal for a solid month now. I dropped a great deal of weight in the first two weeks. Almost 20 pounds! Now I have approached the end of the month and in the last two weeks I haven’t lost another pound! In these past two weeks I have been eating super clean and keeping it strictly to proteins, vegetables and healthy fats. Any insight as to why this is happening, or how to break through this plateau?



Plateaus sometimes just happen. It could be the calm before the storm, and you’re about to be hit with another round of fat loss. So there’s that. You may not have to do anything extra but continue on, sit back, and let it happen.

But often you do have to actively bust a plateau. In those cases, I recommend two things to try before anything else. The first, and most effective? Sprinting.

Sprinting isn’t necessarily the best fat burning lifestyle intervention, but it’s usually the one that kickstarts lagging weight loss. It’s the one that most people are missing. Because, let’s face it: sprinting is kind of scary. For those of us with a history of injuries or bad knees or any sort of soft tissue issue, lining up on a track and sprinting straight ahead is risky and daunting. You can get hurt doing it. You can’t just launch into an all-out sprint cold and hope to come out with everything intact. Most people just don’t know how to sprint because they haven’t done it since they were kids.

Make sure you’re sprinting right. Make sure you’re up on the 19 tips, tricks, and hints for sprinting safely, effectively, and without injury I laid out last year. Make sure you’re practicing mobility work to support optimal movement and tissue health.

Sprinting doesn’t have to be done on a track. You can sprint uphill, which is easier on the joints (and arguably better for fat loss since you’re working against gravity). You can sprint on a beach, which I enjoy.

Sprinting doesn’t have to mean running. You can sprint on a stationary bike. You can sprint in the pool. You can sprint on the Versa-climber, which is my favorite cardio machine of all time and what I use if I can’t run actual sprints. You can also do sprints on the rowing machine or the elliptical. The key is moving really, really quickly for a short period of time.

The second thing to try is a carb refeed. I explained it all in a post, but (long story short) a refeed involves once or twice a week going very low fat and high carb. And by high carb I don’t mean 600 grams. I mean more like 250-300 grams, preferably consumed on a training day to boost insulin sensitivity and restore depleted glycogen. This can raise lagging leptin levels, which increases energy expenditure and reduces appetite, thus promoting fat loss.

Give both a shot and let me know how it goes. Good luck!

Hello Mark,

I am a huge fan and I’ve been looking to implement intermittent fasting as an attempt to restart my weight loss. I want to know if I can get the same benefits from Intermittent fasting if I consume Bulletproof coffee in the morning. The MCT and butter helps me get past the hunger but I want to know if these extra calories reduce the benefits.

Keep up the great work!



Well, it’s certainly not fasting. A half stick of butter and a couple tablespoons of MCT or coconut oil is a lot of calories, and fasting by definition requires the absence (or at least near absence) of calories. Drinking 600+ calories every morning versus drinking zero calories? As far as weight loss goes, the latter option will work better.

A lot of people swear by the BP coffee thing. I’ve never really liked it for myself, not because I disagree with butter and coconut oil in coffee (it’s quite tasty), but because it’s just too much of everything at once. Especially if done every morning. It may be sacrilege among some of you, but I seriously question whether Bulletproof coffee is a good idea on a daily basis. It’s just a huge, unremitting influx of energy that seems a bit too excessive and absent evolutionary precedent for me to be completely comfortable with daily consumption.

Maybe if you’re on a full-blown ketogenic diet and it’s the easiest way for you to eat enough fat. But for the average person on a regular Primal eating plan who likes to eat a wide variety of plant foods and food in general? All those calories you’re mainlining with the coffee in the morning will probably crowd out the other stuff you like to eat.

Go for it if you enjoy it and get good results. But don’t stick with it if you’re gaining weight, feeling nauseated, or any of the other side effects I’ve seen in people (in our own office) consuming Bulletproof coffee (the butter/oil concoction, not the beans) on a daily basis.

Don’t get me wrong: I’m not bashing butter in your coffee. But I’d prefer people think of it as a treat to be enjoyed a couple times a week, rather than a meal replacement or a daily staple. It’s a tool. Hard day of work coming up? Get out the blender and the butter. Just another morning? Maybe make your coffee black and do some eggs, sautéed greens, and a bowl of berries instead for more nutrients, some actual protein, and far fewer calories.

By all means, try both regimens out (fasting and BP coffee) to see what works, but I suspect you’ll have more success with true fasting and intermittent, rather than chronic, BP coffee consumption.

That’s it for this week, everyone. Thanks for reading and be sure to leave a comment with your input down below!

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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