Dr. Boz [Annette Bosworth, MD] - Kickstart Metabolism In 3 Days With Sardines

Why sardines?

Sardines for three days. Why would a doctor recommend that? Let's start by covering the benefits of sardines. Sardines are so nutritionally dense that you might be surprised to see all the stuff that's packed into them. My friend and colleague Judy Cho did one of the best infographics on sardines. Her infographic shows that they're high in Omega-3s, vitamin D, vitamin E, and the kind of calcium that's super easy for your body to absorb, along with important minerals tucked into these little fish.

Let me just brag on how good those Omega-3s are for you. They're good for your brain, your heart, and your overall health. By increasing those Omega-3s, you decrease the risk of anxiety and depression by about 20 percent. The more you increase those Omega-3s, the less you have of Omega-6s sticking around in your body. And I mean sticking around: Omega-6s cause an inflammatory response when they have no Omega-3s to fight against. So keep those Omega-3s high and those Omega-6s a little lower by eating these small, nutrient-dense fish.

What about toxins in sardines?

As soon as I convince people to eat them, they start pushing back about all the toxins in those fish. Here's the rule, folks: the smaller the fish, the smaller the risk of mercury. When the regulators came up with the guidelines on how much mercury we should be eating, they used one of the most conservative approaches, almost to the point where it becomes impossible to have mercury toxicity. For example, the recommendations are that you would have to eat 800 ounces of salmon per week to get close to that mercury risk. What that actually means is you would need a thousandfold that to truly risk mercury poisoning. That's 800,000 ounces of salmon. The point is, you would need to eat so many sardines to reach a mercury risk that it's not physically possible.

The second thing people chirp about is BPA risk, because inside a can of sardines is a plastic lining, and indeed there may be a slight amount of BPA in there. I am not worried about that in my diet, but if you are, you can buy sardines packed in a glass jar.

All right, so the first reason you should eat sardines is that they're so stinking nutritious. The second reason is that it's really hard to overeat sardines. Let me explain. First of all, sardines come in a very convenient pre-packaged dose. Each can is its own serving, and if you're like me, you can eat it right out of the can.

The unique benefits of sardines

The second reason sardines are really hard to overeat is that they induce satiety. When you eat that fatty protein from little fish, it surges the fat-based hormones that are in charge of suppressing our appetite. It surges things like cholecystokinin and peptide YY, and your bile production increases. The bile emulsifies the fat and protein in that fish and allows you to absorb it. If you don't produce enough of that bile, you will indeed burp them up. But it gets better: each day that you do this, today's production of bile is linked to how much you produced yesterday. So each day of the challenge you will get much better with this effect. By the end of the challenge your system will be in full force. You'll be better satiated from smaller amounts of food thanks to your hormones, and you will not be burping them up.

The final reason I like to brag about these little fish is how well they serve your ketones. By the third day of eating them, yes, we talked about those Omega-3s earlier, and indeed they are jam-packed with them. Once they're emulsified by bile and absorbed better, they turn into ketones, and a wave of ketones shows up by the third day. When I'm trying to give a metabolic workout to my patients who aren't so healthy, I use sardines, and by the third day their ketones are the highest they've seen in months and their blood sugars are the lowest.

Sardine fasting vs. water fasting

Okay, so let's get to the good stuff: how do you actually do this? For starters, you'll hear me call it a sardine fast. It's not technically a fast. A fast is when you have salt and water only. Unlike a fast, where people usually start the timer when they finish the last meal, I don't start the sardine challenge until you have the first bite of sardines. I also don't let you end it without eating the last can of sardines at the 72nd hour.

I've helped hundreds of people through this sardine challenge, and I remind them the purpose is to deny food when you're bored or when you're just eating because it's a social thing. I want you to eat only for substance. If you can't get past the flavor, I do let them add some hot sauce. I let them fry them up in a hot fryer; the crispiness can help a little. I think it's important to add pepper. You can even add a little mustard or a tiny bit of relish, but really make sure there aren't any carbohydrates in there. We are trying to stick to food that is highly nourishing, and for that purpose only. It is a time of denial.

The length of the fast is 72 hours, from the first bite to the last can of sardines. During that time there is no eating window. Whenever you feel hunger, eat. I don't care if it's three in the morning: get up and eat a can of sardines. I recommend you don't do this alone. Bring a friend with you on this sardine challenge. Support is welcome, but positive peer pressure is also a way to get you all the way through the 72 hours. You can use their disappointment to help you. Be sure you're checking your morning fasting glucose and your morning fasting ketones. You are going to be amazed at what your numbers are the day after your 72-hour challenge.

If you want to find out my personal reasons for doing a whole week of sardines during a time when I needed less choice and less stress, check out this video. It's pretty entertaining.