---
title: 'Why Everyone Is Talking About Sardine Fasting'
source: 'https://youtube.com/watch?v=C-8H8p6W_9M'
video_id: 'C-8H8p6W_9M'
date: 2026-07-31
duration_sec: 699
---

# Why Everyone Is Talking About Sardine Fasting

> Source: [Why Everyone Is Talking About Sardine Fasting](https://youtube.com/watch?v=C-8H8p6W_9M)

## Summary

This video breaks down sardine fasting, the trending 2026 diet where people eat only sardines for 3–5 days or longer. The host explains its origins, how it compares to the fasting-mimicking diet, its nutritional pros and cons, and whether the health and weight-loss claims hold up.

### Key Points

- **Sardine fasting is the new diet trend** [00:02] — In 2026, the latest popular diet is sardine fasting: eating only sardines for 3–5 days or longer, following the 2025 sugar diet trend.
- **Origin: Dr. D'Agostino and Dr. Hatfield** [00:31] — Sardine fasting was popularized by Dr. Dominic D'Agostino, who learned it from his friend Dr. Fred Hatfield ('Dr. Squat'), a bodybuilder with advanced metastatic prostate cancer who ate one or two cans of sardines per day for a week.
- **A ketogenic version of the fasting-mimicking diet** [02:08] — Sardine fasting is modeled on Valter Longo's fasting-mimicking diet (FMD): 5 days at 500–800 calories, plant-based and low-protein to suppress IGF-1/mTOR and upregulate autophagy. Sardine fasting replaces the plant base with sardines.
- **High protein may reduce fasting-mimicking effects** [03:23] — Sardines are much higher in protein than the FMD, which may theoretically raise mTOR and IGF-1 signaling, so it may not reproduce the same fasting-mimicking benefits until tested.
- **Weight loss relies on sensory-specific satiety** [04:16] — Eating only one food makes people bored and satiated faster, so they naturally undereat. Typical sardine intake is 1–2 cans per meal, leading to roughly 1,000–1,200 calories per day.
- **Sardines are nutrient-dense** [05:08] — Per 100g, sardines contain about 195 calories, 25g protein, 0g carbs, and 10g fat, plus B vitamins, vitamin D, calcium, selenium, zinc, and other micronutrients.
- **Micronutrient wins and shortfalls at 2,000 calories** [06:00] — Eating 1kg of sardines (~2,000 calories) delivers 253g protein, 26g omega-3s, and 30g saturated fat, exceeding most RDAs but falling short on folate, vitamin E, vitamin K1, manganese, and molybdenum.
- **Heavy metals are less risky than can linings** [07:13] — Sardines are small, so they accumulate fewer heavy metals than tuna or swordfish. The bigger concern is BPA and microplastics from can linings; a 2011 study found a 1,200% increase in urinary BPA from canned soup.
- **Verdict: fine short-term, not ideal forever** [09:22] — A 3–5 day sardine fast is likely fine and beneficial, 100 days is probably okay, but a lifetime of only sardines is not optimal. Choose water/brine-packed sardines or fresh fish, and consider sardines as part of a varied diet.

### Conclusion

Sardine fasting is a plausible short-term weight-loss tool and a nutrient-dense, omega-3-rich way to eat, but it is not a proven fasting-mimicking diet. The safest takeaway: enjoy sardines regularly as part of a balanced diet rather than as a lifelong monoculture.

## Transcript

there's a new diet that blows up because people are claiming it fixes their is transforming their health in just a few days. In 2025, all the rage was the sugar diet where you ate zero fat, high sugar foods like fruit, soda, jelly
beans all day and only little protein in the evening. I made a video about my opinions on that. In 2026, the new popular diet is sardine fasting. You just eat sardines, usually for 3 to 5 days or even longer than that. So, the
question is is sardine fasting the next big thing in weight loss or is it just going to share my opinions about the sardine fasting. What is it? Are there any benefits? And should you do it? The sardine fast was popularized by Dr.
researcher of the ketogenic diet and hyperbaric oxygen therapy. He discovered it from another one of his friends, Dr. Fred Hatfield. I like to do what I call, I mean I kind of coined it, it's like sardine fasting.
And I have cancer patient a long time one of the first that I sort of engaged with. Actually, you might His name was Dr. Frederick Fred Hatfield. Mhm. So, he was like kind of a famous >> Dr. Squat? Yeah, yeah, Dr. Squat.
>> Yeah, we were good friends. He was a mentor to me in many ways. But he had advanced metastatic prostate cancer and it went to the bones where they did a PET. And I was just getting into this area of
would do. And I would go to his house and I'd bring him things and he was And he loved sardines. So, he kind I think he steered me onto sardines in like maybe 2007 or eight or something like that. That was my love for sardines
kind of was probably from him. low carb. He called it ketogenic, but I diet. And then he would do five days. He would do a fasting mimicking diet that
Valter Longo has advanced, but he has more of a plant-based approach, but Dr. Hatfield would do Fred would do one or two cans of sardines maybe one can of sardine per day for a week. So, we called it sardine fasting.
In its original form, sardine fasting is supposed to be a more ketogenic version of the fasting mimicking diet created by Walter Longo. So, the sardine fast can be thought of as mimicking the fasting mimicking diet. It's a fasting mimicking
The fasting mimicking diet is a very low-calorie diet done for 5 days to mimic the metabolic effects of extended fasting by keeping your calories around 500 to 800 per day and eliminating animal protein. It's completely
plant-based and low calories to keep the IGF-1 and mTOR signaling low, and you do it a few times a year. There are studies showing that the fasting mimicking diet has some similarities to extended fasting in terms of suppressing IGF-1,
upregulates autophagy, the process of cell cleanup. The idea behind the fasting mimicking diet is that it's easier than an actual extended fast. You get to eat something, although a small amount of food, but your body still
thinks that it's fasting because the mTOR and IGF-1 signaling is low. Whether sardine fasting would provide the same metabolic effects as the fasting reason fasting mimicking diet works is because, yes, it's low in calories, but
it's also very low in protein, which is the key aspect of switching your body from a fasted to a fed state. Sardine fasting might be equally as low in calories as the fasting mimicking diet, but it's much higher in protein, which
theoretically could raise mTOR and IGF-1 signaling. Now, it might be that the sardine fast will still result in very low IGF-1 signaling because the calories by research yet. Now, Dr. Dominic D'Agostino said that Dr. Hatfield
survived his cancer during the time he was doing his sardine fasting, but this have survived his cancer for whatever else he was doing, we don't know. He survive, not just this one thing. Most people who are doing sardine fasting are
doing it for weight loss, though. With the sardine fasting, the idea is normally would. And because you're eating just sardines, you'll probably undereat. Sardines are very tasty, at least for me, and I could eat a decent
you're not going to gorge on sardines. You're not going to eat 10 cans of sardines. You'll just get bored and satiated. By eating just a single food, you're less likely to overeat because of a phenomenon called sensory-specific
satiety. Basically, if you just eat sardines or even just potatoes, you'll get satiated faster and you stop eating because you get bored of the flavor course, and a dessert. That's why they say there's always room for dessert.
Even if you're completely stuffed from the main course, there's always room for is different. So, it resets your sensory-specific satiety. Most people would lose weight by doing the sardine fast because an average
will maybe eat one to two cans of sardines for breakfast, lunch, and dinner. That will still put them in a semi-calorie deficit for the entire day. One can of sardines is only about like 200 calories if it's packed in oil and
around 120 to 150 calories if it's packed in water. So, it's a very small amount of calories. You'll end up getting around 1,000 to 1,200 calories per day if we eat sardines breakfast, lunch, and dinner. The good thing about
sardines is that they're quite cheap and also very nutrient-dense. Let's take a look at the nutritional value of sardines. 100 g of sardines is around sardines. 100 g of sardines is around 195 calories, 25 g of protein, 0 g of
carbs, and 10 g of fat. It's got a decent micronutrient profile as well. 100 g of sardines has a decent B vitamin content. It contains a good amount of choline, small amounts of vitamin A, a very high amount of vitamin D, a good
amount of calcium, copper, iron, magnesium, phosphorus, selenium, potassium, sodium, and zinc. But let's take a look at what does it say when you eat your entire daily calorie requirements with just sardines. So,
let's say around 2,000 calories. That's going to be 1 kg of sardines. You'll get going to be 1 kg of sardines. You'll get 1,950 calories, 253 g of protein, 0 g of carbs, and 104 g of fat. In terms of the micronutrients, you'll get all of your
some. However, you'll be still not meeting your daily folate intake. You'll exceed your daily vitamin D intake, but not vitamin E. You'll also miss out on vitamin K, at least K1. You'll hit your RDA of calcium, copper, iron, almost
magnesium, phosphorus, selenium, zinc, pretty much sodium, and almost potassium. However, not your manganese or molybdenum intake. In terms of the fatty acid profile, you'll get 26 g of omega-3s, which is a huge amount, 2 g of
omega-6s, and 30 g of saturated fat. So, you'll definitely be hitting more than aren't getting enough of there in their diet. You'll get 253 g of protein, which need. That's pretty much twice as much protein I would need, and maybe three
times as much as an average woman would need. And no surprise, you'll exceed all of your daily amino acid requirements. Now, theoretically, based on this, you your life and be just fine. You will only miss out on a few key vitamins and
minerals, such as molybdenum or folate. But, you'll exceed pretty much all the Because sardines are so small and you eat them in their whole size, you're getting also more calcium and collagen that you don't really get that much from
getting a huge amount of omega-3 fatty acids, which do exist in muscle meat and eggs, but in very small quantities. Now, we do have to talk about the higher risk sardines, because the oceans and seas are polluted nowadays. I do think that
the fear of heavy metals in fish, especially small fish like sardines, is a bit overblown. Because sardines are so small, they don't accumulate that much heavy metals compared to fish like tuna, swordfish, or even salmon for that
eating 2,000 to 3,000 calories of sardines every day, you're not going to be exposed to too many heavy metals from the fish itself. Fish and sardines also contain different minerals that help to detoxify those heavy metals, such as
selenium, iodine, and sulfur. If you do a sardine fast for 3 to 5 days once a month, or even if you eat only sardines for 100 days, it's probably not going to be enough to expose you to too many heavy metals. Of course, you can do
a blood test to see if it does, but it's likely that you're not going to see any excessive amounts of heavy metal exposure. The bigger concern in regards to heavy metals isn't the sardines, it's the tin canning. Yes, these cans aren't
but they do a little bit. The tin cans are also coated with microplastics on the inside to prevent all of the metals leaching into the food. So, you're getting more microplastics compared to fresh fish. Eating canned food or canned
fine. Again, a very small amount of exposure, and your body is actively excreting them every day. But, if you're eating only canned fish every day for months upon end, you will be exposing yourself to more microplastics. A 2011
randomized crossover trial showed that people consuming one serving of canned soup over the course of 5 days saw a 1,200% increase in their urinary levels of BPA, which is a type of chemical used to make plastics. So, if you are going
to do a sardine fast, or you like to eat a lot of fish, then try to stay away from canned fish and opt for more fresh fish. If you do get canned fish or canned sardines, then choose the ones that are canned in water or brine,
rather than oil. Even if it's olive oil, it can start to get oxidized eventually. sardine fasting? Well, I definitely think it's healthier and more sustainable than the sugar diet. Theoretically, you could be eating just
not miss out on any significant micronutrients, except for the few ones plenty of omega-3s and plenty of protein. Is it the most ideal? Probably not. And you don't have to restrict yourself to just one single food. And at
the end of the day, the sardine fast works similar to other similar restrictive diets or elimination diets such as the carnivore diet or even the potato diet where you just eat potatoes. Many people have lost weight using that
potatoes and you get satiated, you stop eating. The sardine fast might be slightly different than a standard carnivore diet or definitely the potato diet because you're getting a lot of omega-3 fatty acids as well as calcium
from just muscle meat or definitely not potatoes. The omega-3 fatty acids are deficient in. And these omega-3s have significant anti-inflammatory and anti-dyslipidemic effects when taken at larger doses. And having higher omega-3
lower risk of heart disease, Alzheimer's, and all-cause mortality. So, the higher intake of omega-3s might have some auxiliary or additional health benefits that you don't see from other restrictive or elimination diets. The
higher omega-3 intake will result in lower inflammation, better lipids, better brain health, and better heart health over the long term. Another difference between the sardine fast and things like the keto diet or the vegan
diet is that we're probably not going to see things like sardine protein bars or sardine ice cream like we did with keto and vegan diets. So, the sardine fast will more than likely stay as a whole food diet unless someone crazy does get
mean, it's already a protein bar pretty much. My final verdict is that sardine fasting 3 to 5 days perfectly fine, probably going to be very beneficial for longer than that. Just eat sardines for 100 days, probably going to be fine. Eat
only sardines for the rest of your life, probably not optimal, although possible. incorporates a lot of sardines in addition to other healthy foods, I think diet. The reason for that is because omega-3s, in my opinion, are one of the
molecules that have systemic health benefits on virtually all organ systems longer. Check out this video about why omega-3s are the number one supplement or molecule or fatty acid that can keep
or molecule or fatty acid that can keep you younger for longer.