I Ate 1000 Sardines in a Month... Here's What Happened

I ate 1,000 sardines in a month. Why would I do this? And what did it do to me? Well, sardines, skin, bone, and all, they're nature's protein bar and multivitamin in one. One of the few foods I'd actually call a superfood. So for 30 days, out of gross curiosity, I went full dolphin. And literally, the omega-3 levels in my blood turned more dolphin-like than human-like. And with some tweaks along the way that I'm gonna tell you about, my energy levels skyrocketed. I gained some extra lines, which is always nice, and my strength-to-weight ratio improved along with other weird benefits. But there was one horrible side effect that almost got me to abandon the sardine diet early. So in this video, we're going to break it all down: what happens inside your body during sardine fasting, why it's not a gimmick, how it affects your metabolism, your brain, your blood work. And I'll teach you how to sardine fast or sardine diet to optimize for your goals. So let's dive in. I lost 6 pounds in just the first week. I'm cold resistant. It's a synergy, a metabolic It's like a symphony of a protein bar and a multivitamin had a natural baby. This hormone can preserve lean muscle while extending longevity, like a metabolic holy grail. It's amazing. It's a metabolic paradox. But there was a big problem. Here are my promises to you in this video. First, I'm gonna tell you about my personal experience, the good, the great, the surprising, and even the smelly. Then in chapter 2, we're gonna dive deep into the scientific rationale. I'm gonna prove to you this isn't just clickbait. Although it is bait in a sense, and I'll provide you with a specific modifiable protocol in Chapter 3 so you can use this or a similar tool in your own life if you find what I say compelling. But with that, let's start. Chapter 1: My Experiment. First, the premise. The original idea, the original intent was to sardine fast, meaning eating only sardines to get the benefits of fasting without the harms on lean muscle tissue. This works because the molecular cocktail that is sardines—a combination of omega-3s, proteins, and other nutrients, which I'm going to tell you about later—when dosed appropriately, can permit the benefits of fasting, like autophagy, while supporting the preservation or growth of muscle. But again, I'm getting ahead of myself. For me, this started off as a pure sardine fast. Protocol specifics later, but at a high level, it meant eating about 100 grams of sardines per 50 pounds of body weight, and then supplementing with electrolytes as I needed. I felt honestly great at the beginning. I'm 3 days into the sardine fast, just finished a workout, and I'm feeling great. Energetic, strong, and really light during my workouts. Also, I'm feeling pretty freaking cut, so we'll see if it continues. But at day 5 or 6, and definitely by week 1, end of week 1, I was feeling pretty depleted, to be honest. Now, my hypothesis was this probably because I just wasn't getting enough fat. And energy from my diet in general for my generally lean body type at baseline. I'm a week into my sardine fast and it's going pretty well, but I'm feeling low energy during my workouts. I think this is probably due to just not eating enough fat. I've been salting my food pretty liberally, so I'm gonna try just eating my normal sardines but then adding in fat when I eat them, probably a couple tablespoons of olive oil. We'll see how it goes. Now, I wanna double-click on that because prolonged fasting is not necessarily a bad thing in those who have excess body fat to lose.. But for those who are very lean at baseline, a metabolic stressor like fasting for a prolonged period can provide more harm than good. There aren't particular thresholds. If I were to make up numbers, I'd say maybe 10% body fat for men and 16% for women, but really I'm pulling those numbers out of thin air. Basically, when you're too lean and you fast, your body sends a signal saying, "Hey, listen up. Ignore the internet influencers. You're already low on backup energy support, stored fat. And evolutionarily, that's not great. So we," we being the body, "are going to decrease your energy expenditure and make you hungry and tired until you correct this problem. So what I did, I added fat, isolated fat, to isolate this variable and see if it made a difference. And it was night and day. Specifically, I added between a quarter cup and as much as a cup of high-quality extra virgin olive oil or MCT oils or coconut oils. I'll tell you the difference later. Honestly, adding that fat made a world of difference. It's been 4 days since I started adding that olive oil to my diet and I just feel like night and day more energetic. But anyway, this made the sardine diet quite easy, at least from a dietary perspective. Although there was one major side effect that I'm going to tell you about if you hang on. It's pretty terrible. Brace for it. But first, from a body composition perspective and performance aspects, I felt great. I felt light and energized. I lost 6 pounds in just the first week without a loss in strength or power and drifted down to about 7% body fat. I even had this weird impulse to— and please hang on with me here because this is definitely woo-woo— to consistently invert myself, like on monkey bars or just headstands. I don't think that's scientific, but it was my experience. I don't know what was going on. And weirdly, this is a tad more scientific, within a couple weeks I became cold resistant to an extreme extent. Like I could walk around in 30-degree weather and just take my shirt off and feel fine. And that's 30 degrees Fahrenheit to be clear. This is one of the more unexpected effects of this sardine fast. I'm cold resistant. I just haven't been getting cold, especially outside. Now there's some literature on omega-3s increasing thermogenesis under cold stress, so I'm not sure if that's what's up. I don't know if this is a placebo, but it's really weird. And I might be reaching here, but there are data showing that omega-3s can help promote thermogenesis, the generation of body heat. So on that, and as a biological proof, what was going on with the omega-3 levels in my blood, in my cells? Well, I got some testing and it turned out my omega-3 levels were off the scale, literally. I broke the scale. I got OmegaQuant testing. The reference range only goes up to about 14%, and I was around 16%, which is actually substantially above the quote-unquote optimal range and closer to dolphin levels than human levels. So I was like becoming, you know, in terms of my blood spectrum of omega fatty acids, more like a dolphin than a human, which is kind of crazy. So what are the benefits here? Well, to be honest, we don't really have any literature to cite because levels this high aren't reported in the literature, at least not in humans, maybe in marine mammals. But again, I had great energy and performance. In fact, I even developed the impulse, in addition to inversion, to routinely take the stairs to my apartment. Now, that might not sound remarkable, but I do live on the 37th floor. I'm about 10 days into this sardine thing, and I have boundless energy, so I've just been taking the stairs to my apartment. Let's go, and I'll speed this up so you don't have to watch the whole thing. 25 down, 12 to go. That only 2% of people, when there's an escalator and stairs, choose to take the stairs. And he comes across a pumpkin, go figure. Not even out of breath, not even remotely. But there was a big problem. I was eating so many sardines, as evidenced by my blood work, that a Apparently, I started smelling like sardines. Just giving off a sardine aura. Even when I was fasted, and even when I brushed my teeth until my gums were screaming mercy. And even after I put on rather expensive cologne that I received for my 30th birthday present. But this is not a joke, this actually created decent relationship strife. In fact, and this is quite horrible but true, you guys know I like data, right? Well, my girlfriend threatened that if I continued like this, I wouldn't get much physical affection because the scent and taste were kind of off-putting. My girlfriend is not a sardine fan. "Repetas?" "No!" "What do I smell like?" "You do—" "I do not want to be on camera." "Oh, we can, we can, it can black you out." "You smell like fish, like you smell like you're sweating the smell." "I don't think I can absorb— apparently I've absorbed the fish smell into my skin and now I'm just giving it off. "Ai, sweetie." Even when I'm not eating sardines. "Let me see your hands." No! "Your hands, let me smell this." I haven't eaten sardines today! "Smell it!" No! I'm giving off sardine scent. And in fairness, I told her I was going to track this, but I tracked kisses as data points. So in a blinded fashion, at least blinded to her, I tracked kiss frequency with an emphasis on the window, 4 hours after I had a meal of sardines. And yes, I did brush, put on cologne, And honestly, I stopped tracking after 5 days because true to her word, that number plummeted to zero. Zero kissies. So that made me sad. That was a big downside. And if you try this, I'm truly interested to see if anybody in your personal life observes this. I know this sounds a little bit goofy, but I'm trying something new here and just reporting transparently my own experience with these experiments. So in summary, I felt great. I lost some body fat. My omega-3 blood levels shot up to dolphin levels. But despite my best efforts, I smelled like a fish market. "Wah wah wah wah." So, now with that personal narrative behind us, I do want to get in some more science and highlight some of the benefits of sardines in general and why sardine fasting, or at least a sardine-heavy diet, makes sense from a metabolic, if not olfactory standpoint. So, Chapter 2: The Science. Sardines are a metabolic Swiss Army knife. Seriously. I'll start with the basics. Sardines are nutrient-dense powerhouses. They're packed with high-quality protein, bioavailable protein, and omega-3s, but that's just the headline. When you eat sardines, skin, bone, and all, you're eating whole organisms, everything. That means calcium, vitamin D, B12, selenium, coenzyme Q10, creatine, and more, all in one little bite. On the protein, the protein in sardines is really bioavailable. Meaning your body knows exactly what to do with it. And this is critical during something like a sardine fast, a true sardine fast where you're eating fewer calories and lower protein overall. More on that in a moment. So, in the sardine fast, that combination of zero carbs and low energy, it nudges your body towards longevity pathways, renewal and recycling pathways like autophagy, but you're still getting enough essential amino acids and high-quality protein to at least in part protect your muscles. That's a rare combination: fasted physiology with muscle preservation. It's a win-win, but that's only the beginning. Now let's get on to omega-3s. Everyone knows they're good for your brain and your heart, but here's the plot twist: omega-3s from sardines, they're also incredibly important for muscle health. Omega-3s help fight muscle loss, especially as we age. In fact, multiple studies and meta-analyses show that omega-3s can preserve and even enhance muscle mass, especially at higher doses. Greater than 2 grams, which I was definitely getting on my sardine fast or sardine diet. And mechanistically, omega-3s work by supporting mitochondrial biogenesis in muscles, improving amino acid transport into the body—again, bioavailability but stacked—and reducing inflammation, which is good for muscles. So building up our sardine model here, protein plus omega-3s is a one-two punch for lean muscle mass preservation, even in a calorie-restricted state. But sardine benefits don't stop there. Sardines are also rich in coenzyme Q10, a molecule that supports your mitochondrial health, helps generate energy, and doubles as a potent antioxidant. And another secret weapon in sardines, metabolically speaking, is creatine. Yeah, sardines are one of the richest natural sources of creatine, with levels getting as high as 5 grams per 100 grams. That's in the ballpark of a full supplemental dose. And if you want more on the science of creatine, which is mind-blowing, you can see this content. So in summary, in simple terms, sardines are like if a protein bar and a multivitamin had a natural baby. And it lived in the sea. But we can go deeper. Let's talk about the hormone FGF-21. This is a hormone that spikes during fasting and low protein conditions. It also boosts metabolic rate and helps preserve muscle. Which sounds pretty good, right? But here's the nuance: while sardines do offer this high-quality protein, the quantity of protein you're eating on a true sardine fast or sardine diet is low overall, and this combination—low total protein but rich in nutrients—creates, in theory, a metabolic Goldilocks zone. Enough amino acids to protect your muscles, just low enough in protein to cause an FGF-21 spike, and this hormone helps you burn more calories even at rest. For example, in one human-controlled trial, FGF21 led to an extra 600 calories burned per day. Again, human-controlled trial. And that's ironically the energy equivalent of eating 3 to 4 tins of sardines per day. And you can stack onto that that this hormone, FGF21, can preserve lean muscle while extending longevity, like a metabolic holy grail. It's pretty compelling stuff, and if you want more on that and those science, those papers, see this video. Anyway, let's now not forget. Ketones. My ketone levels were between 2 and 3.3 millimole on my sardine diet. A sardine fast will naturally put you into this state of ketosis, which brings a whole extra set of benefits: more reduced inflammation, sharper cognition, and muscle-sparing effects. And improved cardiovascular health. So now let's wrap up, let's summarize. We've got ketones, FGF21, omega-3s, creatine, CoQ10, bioavailable protein. You can see where this is going. It's a synergy, a metabolic symphony, and all that from one humble fish. That brings us to Chapter 3: The Protocol, or Protocolls. Let's talk implementation. Here's how to actually do a sardine fast or sardine-heavy diet in a way that is effective, sustainable, and maybe even enjoyable. Start with whole sardines. This is essential. This means including skin and bone.— that's a non-negotiable. In terms of packaging, look for sardines packaged in brine, saltwater, or olive oil. Now yeah, there's some debate around olive oil packaging, specifically whether that olive oil fat might oxidize, but honestly I'm not personally too concerned. The tins are sealed airtight and the oil content is relatively low, so I don't think this should be an issue. And if you want to know about my go-to, what I used during this experiment, I used Fishwife sardines preserved in lemon and extra virgin olive oil. So there are a ton of sardine options. My favorites as a go-to are these Fishwife, great, preserved in lemon with a little extra virgin olive oil. But for taste alone, these from Maine are amazing. They're like sardine crack. They're more expensive, so I only treat myself to them on occasion, but they're really good. No brand affiliation there. I just genuinely love the flavor. And that's important, because if you enjoy food, you're more likely to stick with the protocol. Don't underestimate that. I tried a bunch of different sardines, but these were ones that I just look forward to eating. In terms of dosing, a good rule of thumb is about 1 tin of sardines per 50 pounds of body mass. In theory, this helps optimize for ketosis and FGF21 signaling because of the protein dose you're getting, adjusted for your body mass. You'll also need to salt your food liberally to support your electrolyte balance, especially as insulin drops and your kidneys just flush out the sodium. I would say target, and this is a rough target, 3,000 mg of sodium per day. You might need a little bit more or less depending on your baseline, but I think that's a good starting point. Now, next question: how and how long should you sardine fast? The answer is really it depends. My friend and colleague, Professor Dominic D'Agostino, who actually got me on to this sardine thing, uses sardine fasting situationally, as he puts it, like when he's traveling. For 2 to 3 days. I think this is brilliant. It turns a potential metabolic disruption into metabolic wins. And for me, I did like a sardine one meal a day blend for the bulk of my sardine month, where I ate throughout the day mostly sardines and then maybe had one non-sardine social dinner emphasizing seafood fat and zero carbs. And again, for the added fats, I had extra virgin olive oil, MCT oils for a ketone boost, and I could even hit a peak of 6.0 millimoles, which is comparable to what most people get after like a 7-day water fast. Which is pretty cool, right? Now, as a disclaimer, the only time I had a massive excursion was on my 30th birthday where my mom made delicious chicken and tempted me with a platter of my favorite cheeses, so I might have put away about a pound of Manchego and Roquefort combined. Anyway, that disclosure aside, sardine fasting It's amazing. It's a metabolic paradox because you're fueling your body while triggering a fasted state adaptation, fat burning, ketogenesis, cellular cleanup, autophagy, and elevated FGF21 levels. Sardine dieting fasting, it sits at the intersection of science and simplicity. So if you've ever wanted to have your metabolic cake, your fasting cake, and eat it too, keep your lean muscle mass or even build it, a sardine fast or a sardine-heavy diet might be worth experimenting with. Just make sure to warn your loved ones first. Trust me on that one.