I used to find 85% chocolate a bit too bitter, so I normally ate 74%. Then, one week, I found 100% chocolate on offer, so I tried it. It was horrible. But since eating that, 85% tastes fine, so I stopped eating 74%.
You need to eat 100% chocolate with a glass of red wine or port - or grate it into your beef stew, or something. That works, but it really isn't very palatable if you are used to something with sugar in it. 🤑
Thank you Dr. Becky ! It was great to listen to your breakdown on Chocolate. I was pleased to find out that the 92% is best on glucose. It has been my go to for a long while. There are diabetes issues in my relatives . I am not on that list as long as I keep my sugar intake low.
Suggestion, watch a wonderful video by two lovely ladies from Guatemala for ceremonial cacao. HUGE difference about cacao and why. Also levels of cadmium are different depending on where it is grown. You can purchase it and not do the ceremony, but their cacao is not cut with another bean which some companies are buying. No caffeine is to be consumed when ingesting the cacao.
Cocoa butter is the white fat mixed into chocolate to add the fat content & flavor. 100% cocoa has no added cocoa butter, therefore carb heavy vs fat heavy as well as extreme bitter flavor. Cocoa butter is the white substance found inside the cocoa pod (seed capsule) surrounding the cocoa beans. Both are harvested & processed for chocolate products & cocoa butter products & blended together for all the available products available. White chocolate has no cocoa included representing mostly cocoa butter & is very fatty. Gorgeous, important plant: Theobroma cacao!
Great video thank you for sharing the information. Blood sugar is important but also important is the heavy metals of the cacao pods I understand that the cacao from Peru is the biggest culprit of heavy metal
When I eat (here in europe) cheap supermarket 85% cacao chocolate with dinner 20gr., the dinner is 50gr. couscous+1 egg little bit meat n thi sramps my bllod sugar up two hours after meal to 180 and I take berberine 1x500mg with the meal. I ask myself what is wrong here? Ok janumet will lower it more down, I look for a better alternative then berberine. By the way my triglycerides are down form 250 to 120 now (within 2 years done myself) my bad cholesterol is low. So when I live with my daily T2 blood sugar levels at 120-170 with my low cholesterol it should not harm my tiny eye an dkidney vessels ? I askes two medical do's they could not answer my question "it's to theoretical" or they ar eliars ? Is there any better alternative than berberine ?
Every root's (beet's) sugar is harmful 4 the people !!! ! !!! The Cane sugar is what is much more healthy. But, the coffee is the Worse of Alll fooods 4 the Humanity.
Hershey's dark chocolate is probably about 50% cacao, and is not relevant to this study. Only brands that state the percentage of cacao on the front of the label should be considered as "healthy" as opposed to Hershey's which is candy.
I'm not a fan of the chocolate you used for your experiment; I only eat Lindt 90% dark chocolate, its lower in carbs (9g) per 200 cal serving, contains no unspecified "flavorings" and has less cocoa butter than the brand you used. Its expensive and that helps keep my consumption down!
For anout two years i have been using powdered 100% baking caco from the baking isle because it is easier to use than bar chocolate. Its also much cheaper per serving. I just put a tablespoon in my black coffee every morning. Studies show an increase in T-cell production from drinking dark chocolate. Powdered cacao has had the natural oil removed from it during processing. So, I stir in a tablespoon or two of coconut oil to make up for that. Coconut oil feeds your brain in a different way than other oils. It helps with memory and may prevent or slow mental decline in older people. My memory has improved. Also i had a toenail fungus infection for 20 years that grew out healthy again after i started using chocolate and coconut oil in the mornings. I cant explain it. It just happened.
Wow! I'm one of those that buy the 100% Ghiradelli found in the baking aisle, assuming it would give me a healthier blood sugar response. Thank you, Dr. for doing this test. I can't imagine eating 3 squares, at one sitting, of any of these chocolates. I will treat myself to the 86% or 92% from now on. A bit of chocolate makes me happy and I can't leave it behind.
@@Insectoid_2 bars?! Are you just kidding or do you really do that? I mean, I could if I wanted to because I LOVE, LOVE dark chocolate! But I don’t even eat the whole bar in one sitting just to not overeat (I have a tendency to overeat everything I love, especially desserts).
This is simply the best online medical presentation I have viewed in a long time. It was straightforward, well explained, thorough, and the best part for me, Dr Gillaspy pointed out what she didn't know or couldn't conclude and asked her viewers for any additional information that could help her "fill in the gaps." I look forward to catching up on any other videos Dr Gillaspy has online.
I just purchased the Ghirardelli 86% Cacao dark chocolate yesterday, they did not have the 92%, they only had the 72% and 86%. I was diagnosed with fatty liver disease back in February 2023. I took my diagnosis very seriously. I was told by my Nurse Practitioner and a former Nurse/Dietician that dark chocolate and coffee were excellent for people with fatty liver disease. I also used to be a Type 2 diabetic, now, thankfully I am pre-diabetic. I really appreciated this video A LOT. Thank you!
Please try to help me I have type 2 (also thyroid problem without a doctor that knows nothing about thyroid) I did intermittent fasting never had any SUGAR for over a year gained weight I really need help
Montezuma chocolate 100% is delicious. Like Tea, coffee and beer, it’s a taste that has to be acquired. This doesn’t take long and, melted slowly on the tongue, a small amount goes a loooong way ❤
As a type1 diabetic for over 25 years (pancreatic failure), I find that if you had a healthy lifestyle pre diabetes and didn't over do it with garbage.. go back! Most of these over thought diet changes are relying on factors that most can't realistically uphold in their day to day, life isn't in a lab. I work outdoors and some of it is labor intensive at high altitude and other days it may change. My A1C is less than 6.8 mmol/L or 42 mg/dl and I'm not obese (110k 6'2" active male). I can eat any chocolate in moderation, but also keeping in mind that some fiber has to be compensating those sugars I eat. Everyone is different in some way, whether it be with daily exercise or diet requirements. I went through my dietician almost turning me into a 60k waif that could no longer work my job, just don't seem to understand a working body, but rather a more sentry model is used instead.
Thank you so much.I eat the 92% chocolate, one piece usually after my evening meal, which finishes with the treat. I eat Keto and have only two meals a day. I am pretty healthy for 87, am 4.11 and weigh 101.
My normal choice is 85% chocolate of a different brand, but I'm sure the results would be similar to the 86% you tested. Some 90% has been "treated with alkali", which removes some flavanoids, removing the bitterness, but presumably some health benefits as well. Thanks for doing this "difficult" research for us.
This is a VERY important point: ANY cacao bean that had been treated with alkali and extracted the cacao (it’s called Dutch method) as the ingredient for making the chocolate bar has not much antioxidants value left, because this method destroys them. So, without knowing whatever brand of chocolate that you are consuming, how many sugar or butter is added to make it much more palatable, if your goal is to obtain the rich antioxidant benefit (purported to be 10x higher than blue berry) then you need to find out HOW the manufacturer processed their original cacao bean. The rise of blood sugar (glucose) level is a function of whether the chocolate contains any carbohydrate or added sugar, AND a person’s ability to handle the ingested carb at the amount (dosage) of the glucose equivalent - in other words, the person’s glucose tolerance (resistance, if any). There is no antioxidant benefit from the far that is contained to various amount in various brands of commercial chocolates , so one should avoid buying any products that contains sugar or fats, just use 100% cooking cacao powder that is non-Dutch method treated. Too bitter, use sugar if you don’t have any pre-diabetes or diabetes in you, or use Stevia leaf product [without added Erythritol !] One can find out the antioxidant content and comparison in Hershey’s website and other professional articles about this subject.
@@tequila_tibbs7938 If a bar is treated with alkali, it will say so on the label. It may say "treated with alkali", "dutched" or "made by dutch process". Lindt 90% bar says "cocoa powder processed with alkali". The Lindt 90% bar has low sugar, which is healthy, and it tastes good, with the bitterness removed, but yes, flavanoids have also been removed. It's up to you to decide which traits are most important, flavor, low sugar, or anti-oxidants.
I wonder if Ghirardelli is listing ingredients accurately now. Years ago I kept having gluten reactions to their chocolate for no apparent reason, so I contacted them overseas to find out why that might be happening. "Oh, we add barley malt," the lady at the factory told me. "It's not on the label!" I answered. "Aren't you legally required to put that on the packaging?" (Then I explained how severe gluten sensitivity can wreck my mind severely for 9 days; I get "forget to go to your job" and "can't find my way through airports" stupid, so this is not a minor issue in my life). It still takes so much research to know about all this stuff.
I hear you. I picked up a 90 something percent dark chocolate bar at Trader Joe's recently and was really enjoying my one or two squares per day until I read the ingredients a few days later - soy something or other. DOH! I have auto-immune thyroid disease and soy is at the very top of the "no eat. None. Not even a little" list because soy blocks TPO enzyme. Why, Trader Joe's would you add soy to dark chocolate? Soy? Chocolate? WHY???
Recently I've been hearing about high levels of the heavy metals; lead and/or cadmium in dark chocolate. I am glad you tested Ghirardelli, as their 86% and 72% have been tested and fall in to lower/acceptable levels. Consumer Reports, NPR and NYTimes have published about this issue.
I love 92% dark chocolate by Girardelli...you can buy it in individually wrapped squares. It has a natural, subtle sweetness, but I love it because I know when I eat them that I am getting a great dose of good things! Hope you have a great week Dr. Becky!😊
I’m almost 2 weeks in to this new lifestyle. I’m focusing on no processed foods, it’s going really well. I was so addicted to sugar, and right from the start , with eating good fats, I’m not craving sugar . I’m not hungry and don’t have the need to snack. This is an informative video, thank you.
@Tom by processed I meant processed and refined boxed food , pasta , bread. I try to eat food in its whole form; fruits, vegetables, nuts , seeds, meats and dairy . Although meat and dairy are processed, I meant the carbohydrate kind 😊😖
Im doing the same. I eat minimally processed - cheese, yoghurt etc but no sugars or sweeteners or flour. I eat wholegrains - brown rice, spelt, wheatberries. I am a sugar addict and im only two weeks into this new lifestyle but less cravings already and iv lost 7lbs without trying. I didnt do it for weightloss but i am over weight.
I was terribly addicted to sugar. After weening myself off sugar, I lost my typical 5 to 8 cup a day craving for coffee- always with a couple of grams of 'healthy' natural Turbinado sugar. Healthy- imagine that. Good luck and stick with it always.
This is extraordinary, I would have bet real money on the 100% being the best! Thanks for doing this for us, I love your channel particularly your quiet pleasant presentation style. Great advice, well delivered.
thanks for a great analysis -- I think I'd choose the 86% because you recovered faster from the rise even though it was 6 higher than the 92%. I'm learning from levels that the trend line is very important not just the numbers... so I watch how fast I rise AND how quickly I recover. Of course I would need to test myself for both since my response is likely different :)
The Consumer Reports lab found that out of the 28 dark chocolate bars, eight had more than 100% of the MADL of cadmium in a single ounce. Ten had more than 100% of the daily allowable dose of lead per ounce. And five contained more than 100% of both cadmium and lead.
I eat Lilly's chocolate which is made with stevia and it has given me the chocolate that I like with no craving -- I do not eat all of their chocolate products but the dark chocolate and the one with almonds -- both are great -- and have never caused any sort of GI reaction. Enjoy!
Lily's has erythritol which destroys some people's gut lining and can aggravate all kinds of gut issues!! I met the people who created it and they had first got it on the market I tried to talk them out of having erythritol in it but it was too late. I notice for years now in the stores like Whole Foods where I live, all the chocolate brands will sell out at Christmas and Valentine's except Lily's, which stays mostly untouched & full on the grocery shelf! If you have gut issues or develop them stay away from erythritol!!
I've been adding 2tbsp of 100% cacao powder to my coffee every morning (can consume up to 4tbsp/day for optimal benefits) because I also read a study that doing so will significantly increase red blood cell count. I'm going to request a blood test. Anyway, I'm curious if you could try powder version in even hot water and or if the nutritional composition is different.
I drink 100% organic cacao powder with milk and coconut oil and butter in it, i love it, so silky…first i put the cacao the butter and the coconut oil into hot water, until the butter is melted then give the cold milk and blend them to have a foamy, silky drink…just amazing
My goodness on the Levels membership! I paid $59 for a Ketosis/ blood sugar monitor AND it comes with a month supply of tester strips.. Keto-Mojo is the brand, I love it so far. Really excellent video, thank you for doing this!
Set your playback speed to 2x and you will be able to make it through this otherwise slow and laborious video to get to the conclusions. Please try to keep your videos under 5 minutes and just get to the point.
I buy the Lily’s brand dark chocolate with stevia when I crave chocolate something. Your stevia sweetened bar looks like a milk chocolate. Too bad they haven’t labeled it in cacao%…I’d leave that on the shelf at the store🥰
I love these videos where you test different foods to compare sugar and/or ketones! I just found your channel and have been binge watching these types of videos! I also love the calm way you teach and you do a great job of including the realities of sugar/ food addiction. I have joined your Freedom program and look forward to seeing what it does. My husband and I ate plant based low fat for 2 years to try to reverse chol and artery plaque build up. This did help but was hard to make lifetime eating. I don’t think was healthy without healthy fats. The first night we ate your recipe chicken Alfredo with rice I was scared to death we would have a heart attack while sleeping! The thing that draws me to this eating is the reality of my sugar and binge eating which never went away, though it was better with the Plant based low fat eating. We will see! I’m hopeful and anxious to see what cravings and blood tests reveal!
@@Starfish2145 That's what I was thinking. It is really hard to eat chocolate over 85-86%. The difference was 1 point, so I would have to give that in order to enjoy my chocolate - and it would still be a world of difference better and a huge improvement to what I have been doing.
Thanks for conducting this experiment which seemed to at least validate what I experienced (although the cause remains unclear to me). FYI - I found this video after searching for an explanation of why an unsweetened organic cacao powder appeared to spike my blood sugars. I did not test at the time to confirm it. However, I know my body and how it responds to raised blood sugar levels. I had been meticulously practicing ADF and low-carb before the experience. Surprisingly, the nutritional label shows only 3g total carbs and 0g total sugar per tbsp. New subscriber here.
Decades ago I watched a program on how a snack food is created. It went from development to marketing. What I still remember is how the small ingredients are added and adjusted to create consistency and a long shelf life. The sugar, the oils, the flavors; all very small amounts compared to the main ingredient, but they were very carefully added and adjusted.
Good day Dr, from South Africa. I’ve been following your channel for 2 months now, I am very strict to a no sugar no bread diet and in the process lost 20 lbs. Feeling absolutely great and my sugar down from a 13 to 6.5. Thanks for sharing your knowledge although I’m 6000 miles away I’m benefiting from it.
Good to know that calories are not rigid - Love this test and will continue with portion-controlled occasional chocolate treats of 85% (other brand) Thank you Dr. Becky! Love your videos!
I use Our Finest brand from Walmart Canada. (90% and 85% Swiss Dark Chocolates bar). I smash the bar and put the tiny bits into (unflavoured) Greek yogurt, berries, chia seeds, cinnamon and coconut flakes.
You are a true pioneer! Taking one for the team and testing on yourself. I love that you do these tests. I look forward to the next one. I am nervous about using foods with"natural flavors". I have read articles where they say they are allowed to use hundreds of chemicals and don't have to tell you. Thank you for all your research.
Having to eat chocolate for four days for scientific research...such sacrifices. Thank you actually. Dark chocolate is not something I can give up entirely but I am trying to be careful so this is very useful.
I have shown Lindt chocolates as an example in a past video. But I never included it in a blood sugar test. I chose Ghirardelli to stay consistent with my first round of testing.
Excellent video, however, I ate dark chocolate daily for 3 years until a comprehensive study found that the majority of them contain very unsafe levels of cadmium and heavy metals. Specifically, dark chocolate had, on average, 7.6 micrograms of cadmium and 0.8 micrograms of lead per one-ounce serving, and some products had three or four times as much. Look it up.
Alter Eco Mint Blackout, 90% dark chocolate with a hint of mint that makes it my absolute favorite dark chocolate bar. And it is a good do-right company.
Lindt Excellence Dark 99% Cocoa is delicious! I always ate 85%, and accidentally bought a 99%, probably thanks to someone who put it back in the wrong place on the grocery shelf. At first, I thought it wasn't sweet enough. But, with time, I grew to prefer its rich, intense taste - especially with a nice glass of red wine! 🍷😋
@@johnburrows3385 - I totally see where you're coming from. I didn't like it the first time I tasted it either. But then I tried it with red wine, and voilà, the combination of flavors was very enjoyable! Mind you, a 50g bar consists of 12 squares, and I only eat one square whenever I do indulge.
I've been doing low carb for years, but the craving for a couple of squares of dark chocolate after most meals never went away. My favorite is the 72% fair trade, organic, Belgian dark chocolate from Trader Joe's.
@@jarhead4657 ya, sorry, we were disappointed too, as I used to get their 1 lb dark chocolate bar. They took many chocolates off the shelf in our TJ'. I saw the articles first hand.
You have to look at the lead/cadmium content too. You want the lowest possible - well below 100. It’s not just the sugar you have to be concerned about. Not too many chocolate brands meet this criteria sorry to say.
On the calorie discrepancy question, I would look to the actual fiber that may or may not be in the chocolate bar. Cocoa comes from cocoa beans, they have protein, they have fiber, and the actual percentage of ingredients in the bar could definitely be different than what we’re assuming is the case.
I’m not an expert but I heard that chocolate is made up of cocoa solids and cocoa butter. The percentage of chocolate on the label just reflects the combination of the 2 ingredients. The proportion of the 2 ingredient is not listed. Therefore, even if the percentage listed is the same, the nutritional information can be quite different.
I recently shifted from 90% dark chocolate to 70% dark chocolate as most raw chocolate sources have unacceptable levels of heavy metals such as lead and cadmium. I am in a dilemma after watching your results - I think I will shift back to 90% but consume a smaller quantity (10 gm instead of 30 gm). Thanks for posting the results.
You're the only person I've seen comment in this. To me, the lead is of MUCH greater concern than the blood sugar levels. That needs to be addressed by the industry and solved, it is completely unacceptable. They're selling us poison, and much worse, children are eating it.
Thank you. The 100 % has been my chocolate fix. It does take a while to adjust to no sweetness, but the rich creamy mouth feel was great. One of the rules of a keto diet is food companies lie on their labels.
Thanks for this video. I was diagnosed with Type II diabetes a year ago. Following a change of diet my blood test levels are now normal. However, I still think I have insulin resistance, so am still moderating what I eat, whilst making sure I do not put on weight. My local shops in the UK sell 85% and 90% chocolate and I have not had any noticable ill effects from eating them. However, I will up take your recommendation to eat in moderation and so will try(!!!) to only eat two squares. Many thanks.
❤❤COMENT, It’s exactly that Ghirardelli’s baking bar, just one square (I cannot find it where I’m now) that I miss, BECAUSE it’s the one I get the best effect with a shot of Itoen oolong tea, on an empty stomach, just one square, , With other chocolate brands the effect is less, And not so much with the green tea either which is supposed to have more theanine, I did google searching and did not find satisfactory reason, I can say that I have replaced the itoen with a glass of red wine and washed down the chocolate, the effect is good, better than either alone but with the oolong is nicer, it lasts me for about 1 to two hours, very relaxed, good mood and alert❤❤
Very interesting report. What Levels is doing is great and it was great to see through your video how individuals can do their own testing of their individual variation. Your sacrifice in forcing yourself to eat chocolate is also appreciated.
When people say they "like chocolate", it usually translates as "I'm addicted to sugar", since there's very little cocoa in the product. Your calories query is interesting and suggests that Nutrition is not an exact science!
But why with coffee??? We know that coffee on an empty stomach leads to a massive insulin peak. Is it then not likely that the higher FAT content of the 92% variant alone led to the best result?
Thank you for doing this test, it was brilliant. I'm a 63 year old female, at a healthy weight and zero heath issues. I'm on the carnivore diet to remain healthy. With that being said, you can understand why I feel it's okay for me to eat my favorite treat occasionally, yes . . . chocolate! This is why I appreciate that you tested the different chocolates. You did a fabulous job of picking the test bars and brand of sugar sweetened. The only thing I would have suggested is that the artificially sweetened chocolate should have been any brand that was actually labelled as 92% cocoa. That would have made your test as perfect as possible, in my estimation. For instance, I eat a brand that is labelled 92% cocoa and uses artificial sweetener. Since your artificially sweetened cocoa bar was not clearly labelled with the cocoa percentage, it makes the test of an artificially sweetened bar, worthless to the viewer. Obviously, I'm not suggesting you re-do the test or make a video with an update. As of right now, it wouldn't be cost beneficial for me to get a glucose monitor just to test my favorite treat so I'll continue to eat my 92% cocoa that is artificially sweetened and simply hope it's the best option. Thank you again for the fun video. You're an excellent presenter and I enjoyed watching.
I think the labels are wrong The 100% product might be dodgy. It is sold as cooking chocolate . Lindt 95% tastes very good not bitter. If there is a 100% I haven't seen it here where I live ( Australia) The 70% Lindt is oversweetened a nd the 85% is good Interesting result and a great lesson in not making assumptions
You need to watch Dr Robert Lustig. There isn't just "carbohydrate" and there isn't just "sugar". There are 2 main monosaccharides. Glucose and Fructose. The Sugar in blood is mainly Glucose. It's what your monitor tests. When most people say "Sugar" they mean Sucrose which is 50% glucose and 50% Fructose. So the bit of the label that says "sugars" is meaningless when it comes to indicating what will happen to your blood glucose unless you know what sugar it is. If it's high in Fructose then your glucose spike will be low. However, the Fructose will go to your liver and be converted to fat, which may be problematic, ie NAFLD.
I have been choosing the 90% Lindt bars simply because I got zero pleasure from their 100% cacao bars. Thank you for confirming I was making the best choice. 🙂
@@spandel100 Target sells the 90% Lindt bars for less than $4 (at least in San Francisco). You may want to check your local Target. Also, Amazon has it for $3.69 per bar.
Leaving chocolate at the grocery store is SACRILIGE! It's completly satisfactory to INCLUDE a 200 calorie square of 92% chocolate in your diet! That is much better than 200 calories of starchy junk food! Thank you for the EXCELLENT analysis of the dark chocolate! There are more categories of foods you can test in the same way!
I appreciate these testing vlogs and find them informative and entertaining. However, I don’t plan to indulge in any chocolate (dark or otherwise). I know my limitations and Dr. Becky’s video “Programmed to Overeat” helped me to understand my decision.
You get various 100% chocolate varieties from different brands here in Europe in Health food stores, specialized chocolate stores and more high end supermarkets. I love that you can actually taste differences based on the country of origin, similar to high quality coffees. Trinidad is my favourite. The flavour profiles are so much more defined, it is not just sugary like the regular dark chocolates with added sugars. Isn't the conching and fermentation process very different for bakers chocolate? I cannot imagine eating that.
I don't think antioxidants are a realistic measure of the benefits of cacao because it is also high in oxalates, which is a problem for many of us. I do love dark chocolate and for the first 4 or 5 years of my very low-carb lifestyle I ate a lot of it in the 88-92% cacao range. But a couple of painful bouts of oxalate overload, due to things like nuts, spinach, kombucha, and my dark chocolate habit, made me realize those things are not my friend. I now eat a near-carnivore diet, which means I'm not eating oxidative foods and am getting a ton of methionine, the best antioxidant there is.
I used to get my chocolate at Trader Joe’s and usually stick with 80% or more, but sometimes I would get closer to 70% and I even tried 90-100%. The latter was least enjoyable and as a result harder to stick with. Thank you for sharing your results which are very helpful and informative.
Have you viewed a channel called 'Nourished by Science'? Mario Kratz, PhD has some very interesting videos on Insulin spike and combinations of fat, protein, and carbs and their effect. In his analysis, he's seen that a simple carb eaten alone spikes much higher than a simple carb taken with say a healthy fat or protein. How to Avoid Blood Sugar Spikes (Without Reducing Carb Intake)- in this video, e's not recommending eating simple carbs, but offers the advice that if one does, combine those simple carbs and or starchy foods with healthy fats, protein, and cruciferous vegetables. I'd love to see a zoom collaboration between you and he on that subject.
Well, I think for the sake of science, I should probably start eating chocolate for breakfast as well. Maybe even for lunch and dinner...but only because of my deep love and devotion to furthering science, of course.
Maybe testing several different brands of sugar free chocolates would make a good video. Example Lilly's chocolate bar, chips, etc vs others'. Thanks for your "research":)
We are daily being manipulated by the "serving size" listed on the package. It's kind of like the unit pricing on everything. For example; A can of a certain brand of coffee, doesn't seem to change, until you realize the 1 pound can is now 10 ounces, the price of 5 pounds of sugar is now a 4 pound bag for the same price. Anyway, please remember you are an incredible educator and way to valuable to those of us that learn from you. Please be extremely careful in using yourself as a laboratory subject.