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Join me in making healthy choices guided by science - not spin.

I'm a scientist who loves helping people make healthy choices about food, fitness, vaccines, and more. I hope you enjoy my collection of digestible science and delicious plant-based recipes. Thanks for visiting!

Chana Davis, PhD

RECENT POSTS

Join me and Dr. Deirdre Tobias for a chat about nutrition studies and headlines. I for one welcomed the change from COVID COVID COVID!

Dr. Tobias is an epidemiologist who specializes in nutrition, obesity, and methods at the Harvard TH Chan School of Public Health and Brigham and Women’s Hospital in Boston. @harvardchansph

Our chat explores two broad issues that underlie flip-flopping nutrition headlines.

👉Problem 1: Nutrition research is HARD!

To draw firm conclusions, this is what you want in a study:
✅Large HUMAN trial: This minimizes the impact of chance and enables generalizable conclusions.
✅Long duration: It takes many years to see the impact of diet on most diseases.
✅Well-controlled design: We need to rule out the placebo effect. We also want the control and treatment group to only differ in a single way (your test factor).
✅High adherence: Ideally, all subjects follow their “prescription” perfectly.

See how hard this is?! It’s all but impossible to enroll thousands of people, create two groups that differ *only* with respect to your nutrient (or food), have them follow it perfectly long enough to develop (or not) the disease you care about.

In practice, all science involves piecing together the patchwork of evidence from a lot of imperfect studies, with a keen awareness of their limitations.

👉Problem 2: Clickbait.

For the reasons above, a single nutrition study can rarely give a firm causal conclusion like "chocolate prevents cancer". We should always consider the weight of the evidence.

Yet, certainty sells. Shock sells. So, the press often distort and exaggerate scientific findings.

⚠️Look out for giant leaps science to headlines. Was the study in humans? Was it a large study? Did it use a relevant dose? Did it measure the outcome we care about (like cancer) or a near term proxy (aka "surrogate biomarker").

🎧Check out Get Real Health Ep 38 for more insights from the frontlines of nutrition research including concepts like causation, confounders and chance (p values).

Thanks for listening and sharing!

Link in bio or go to my website:
https://fueledbyscience.com/podcast/

#fueledbyscience #podcast #nutritionscience #nutrition
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Go to COVIDtests.gov to order four free rapid antigen tests per US household. Tests will usually ship in 7-12 days.
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🧪The website also explains other recent actions taken to expand testing access including the requirements for private and group insurance to cover rapid tests, and expanded community sites.

🐴This is clearly a case of too little too late. The US has a long ways to go on the testing front (as does Canada, my home turf!). Please take advantage of this resource. As they say, don’t look a gift horse in the mouth.

⚠️Omicron is changing the game for rapid tests. A single negative rapid test is not a green light, especially in the first few days.

🔥Tip: Use your tests at least 5 days after an exposure or a few days after symptoms for a more conclusive test. Re-test in 1-2 days test if negative. While in limbo, assume you could be contagious .

👩🏻‍🔬Keep following for updates as the science is coming fast and furious. Also, check out @dear_pandemic and my newsletter collabs with @your_local_epidemiologist .

👩🏻‍💻Stop scrolling and place your order NOW (if you are in the US!).

Links:

UPDATE on detecting Omicron with Rapid Antigen Tests (Dear Pandemic)

https://dear pandemic.org/detecting-omicron-rapid-antigen-tests/

Antigen tests and Omicron (YLE)
https://yourlocalepidemiologist.substack.com/p/antigen-tests-and-omicron

#fueledbyscience #rapidtest #rapidtestcorona #covidtest #covidtesting #rapidantigen #lateralflowtest #antigentest
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Testing, testing...1 2 3! Given my obsession with all things testing, I thought I'd share some pro tips, and a bit about my background.
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💕My nerdy love affair with all things testing (screening, diagnosis, and more)
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During my PhD, I studied the gut microbiome using a DNA microarray that I designed and validated (before DNA sequencing was so cheap!). We followed healthy babies for the first year of life, at a time when very little was known (back in 2005!).
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After grad school, I worked for a foundation dedicated to early cancer detection. We partnered with academics to discover and validate new ways to find cancers early, when they are easier to treat. It turns out to be very hard to find markers that are both specific and sensitive. We still have a long ways to go.
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Next, I worked at Genentech / Roche, in the Oncology Biomarker Development. Our mission was to develop tests that could predict which patients were most likely to respond to a drug. I am still huge believer in the power of precision medicine.
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Finally, I moved home to Vancouver and worked at Genome BC where I co-led a white paper on personalized medicine, before switching gears and starting @fueledbyscience.
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🔥Tips:

➡️ Be leery of unapproved tests and unvalidated claims. When in doubt, check the relevant regulatory website (e.g. FDA, Health Canada). Illegit consumer tests are common.
➡️ Focus on fit-for-purpose, not perfection. The best we can do is use the right test, at the right time, and interpret with a full understanding of test limitations.
➡️ More testing is not always better. An accurate test can give misleading results in the wrong population. Indeed, a test with 99% specificity could give far more false positives than true positives in a low-risk setting (like prenatal screening for rare diseases).
➡️ Test performance in the lab, with ideal samples (analytical performance) does not always predict real-world performance. The real world adds many layers of challenges like disease biology, sampling, processing and more. With rapid Ag tests, real-world data are slowly emerging.

Thanks for being part of this community!
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📸 @zukirose
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#fueledbyscience
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If Omicron hits your home, don't give up. With a proactive approach, luck, and resources, you may not all go down. I hope our story offers a glimmer of hope, and some useful tips, to others.
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Our story
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🎄On Christmas day, we learned that our 10-year-old son was potentially exposed to COVID-19 two days earlier at childcare. We rapid tested and got a faint positive with BTNX. The next day, his rapid test was bright positive.
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🎉That was 8 days ago. Amazingly, the rest of us are still feeling good and rapid negative (mom, dad, twin 6-year-old sisters). Thankfully, my guy has had almost no symptoms - just a bit of a stuffy nose.
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Our approach:
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😷Stellar masks. We didn't feel comfortable isolating our son so have been spending time together wearing CAN99 respirators (N95 caliber). Our son has been only removing his mask when eating, and doing so in a different room than the rest of us
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🛏Separate bedroom and bathroom. We are so grateful to have the space to do this.
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🛑No sharing. Our son has had designated dishes, toys, and seats. We used visual cues like stickers on his toys, a rubber band on his cups, and a red paper "placemat" as reminders to all of us not to touch his stuff.
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🧼Hygiene. We are washing our hands often and wiping down common touch points.
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More tips to #stopthespread:
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🧪Test early and often *if you can get your hands on tests*. Many kids are virtually symptom-free yet can spread to others.
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🤒If you have even mild cold symptoms, assume it's COVID-19 until you can get tested (even then, you'll want more than one negative rapid). Better safe than sorry.
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🤳Tell your contacts so that they can find out before it's too late.
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🤗While precautions can be effective, don't beat yourself up if you can’t keep Omicron away despite taking precautions. All we can do is our best. For many people, it's simply not feasible to do it all - due to young kids, lack of space, resources etc. Plus, there's not much you can do if you catch it after it spreads.
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👇Please share your #omicron stories so that we can all learn from each other. Good luck and stay safe.
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#fueledbyscience #omicronvariant #omicron #stopcovid19 #rapidtest
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A few hours later, this guy tested positive for COVID. On day four, he's still bouncing off the walls. Zero symptoms. Honestly, a little fatigue wouldn't hurt! 🤷🏻‍♀️
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👋Consider this a nudge to those you who don't think your kid needs a COVID test due to lack of symptoms.
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I realize that both PCR and rapid tests are very hard to access right now. In fact, my son didn't "need" to be tested according to the online testing guide here in BC - no symptoms, plus, a first vaccine dose a few weeks ago. But, these guidelines reflect limited resources. It’s impossible to predict perfectly.
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🧪Please fight for testing, if at all possible. Knowing your status can fortify your resolve to make sure you don't spread it to others in the home and beyond. Personally, I find it hard enough to keep my guy isolated from the rest of us knowing he is positive, let alone in a "maybe he's positive" state of mind.
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💻Check out your local health authority website for testing sites. If you're in Vancouver (like me), you can get rapid tests at UBC. It was only a short wait a few days ago. In the US, check all major pharmacies often.
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⚠️Remember, one negative rapid test is not enough, especially in the first few days after exposure or symptoms. With Omicron, rapid tests can turn positive as early as 48 hours after exposure (like my son) or as late as a few days after symptom onset. Stay tuned for more on detecting O.
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If you think you *may* be positive due to mild symptoms of possible exposure, please assume you are, and act accordingly until the clock runs out or testing can rule it out (*repeat* rapid tests).
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❗️Just because COVID is mild with many kids doesn't mean it's no big deal. You never know who will get unlucky with short or long term impacts. Plus, it's a different matter for the vulnerable people that we can unknowingly infect - and our overwhelmed healthcare systems and professionals.
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PS So far, knock on wood, the other four of us have escaped, but this could change by the time you read this. Our home is a high-risk exposure zone until my son clears it.
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#fueledbyscience #covid #pandemiclife #omicron #omicronvariant #omicronishere #covidinkids #stopthespread
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If you're isolating right now due to a positive test, exposure, or simply to be cautious, I feel you. It sucks.
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The #omicronvariant is inanely contagious. Even some of the most cautious people I know are getting it, often with no idea how.
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Know that every COVID case you prevent spares many more. Down the line, one of those cases would have been serious. You're also sparing overworked healthcare workers and systems that we rely on for so many other conditions beyond COVID.
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Thank you for doing the right thing. Hang in there. We're in this together.
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#fueledbyscience #covidpositive #omicron #covidvariant #pandemiclife #stopthespread #stopcovid19 #healthcareworkers #hcw #hcwshoutout #healthcareprofessional #healthcareheroes #covidisolation #covidquarantine
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Ho! Ho! ...Nooo! Santa brought us an unwelcome gift. #omicron
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After a lovely Christmas morning, things went downhill…fast. I got an email notice that my kids were *potentially* exposed in childcare on Thursday. A staff member had just tested positive. We were told it was not a "close contact" situation.
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We immediately tested all 3 kids with my stash of BTNX Rapid Response. I thought 48 hours was too soon to see a signal so was shocked to see a faint line for my son. We re-tested my son with another brand (Hotgen) and again saw a faint line. At that point I figured it was a true positive, on the cusp of taking off. We acted accordingly.
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Sadly I was right. The next morning, we tested the whole family using Abbott Panbio from the gov testing site (no more PCR!). My son was bright positive (with Abbott Panbio and BTNX). The rest of us were negative. I am highly suspicious that it's Omicron given that it's dominant here, plus the speedy timeline - 48 hours from exposure to faint rapid pos.
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We're testing every morning to see how the dominoes fall. In fact, one of the few silver linings of this ordeal is that I get to be a lab scientist again! I'm enjoying being on the front-lines of seeing how rapid tests work for Omicron, and am very encouraged so far. That said, other citizen scientists (Twitter anecdotes) have said they didn't test rapid positive until a few days AFTER symptoms. It’s the Wild West.
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It will be a miserable few weeks as this takes down our family. I hope that our saga can help others in some way. A few lessons:
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👉Tell others if you *MAY* have exposed them. It doesn't take much with Omicron. Hats off to our childcare for taking matters into their own hands since standard government channels were closed.
👉Test early and often. I'm so relieved that we didn't expose others due to early notification and testing.
👉Take faint lines seriously.
👉Assume Omicron is everywhere and keep using layers of protection.
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🙏I'm feeling very frustrated, yet grateful that things are mild (so far) and that we have the luxury of taking time off from work. This has - and will - be a lot worse for many other families.
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⚠️Stay safe!
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#fueledbyscience
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So far, things are looking very good. Every rapid antigen test (lateral flow assay) product is unique, and is being re-validated.
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In silico (computer) analyses look promising for many tests. A few tests now have excellent lab data. Stay tuned for more lab and real world data to rule out subtle impacts.
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TEST BRANDS
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In North America, we've seen positive statements from: Abbott (BinaxNOW), Quidel (QuickVue), BD (Veritor) and BTNX (Rapid Response) and more. UKHSA shared stellar lab data for several brands (eg Innova). Check with test manufacturers for the latest updates.
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RAPID TEST SCIENCE
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🔐 Rapid antigen tests (aka lateral flow assays) involve test antibodies binding to a bit of viral protein. Think lock and key, or Cinderella’s slipper - it has to fit just right!
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💻 In silico (computer) predictions give a solid sense of whether this delicate interaction is altered for a variant, based on its mutation profile. Lab experiments are needed to rule out asubtle changes, especially if there are mutations near the test target.
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🤓 Nerd Note: Rapid antigen tests often target the N (nucleocapsid) protein. The Omicron variant has four mutations in the N gene - but this is not a deal breaker. As long as the mutations don't alter the tiny piece detected by rapid test antibodies, we’re in good shape. This is why lab and real-world data are crucial.
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WHICH VARIANT DO I HAVE?
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🦠 Standard diagnostic tests (both PCR and rapid antigen tests) can't tell you which variant you have, they just tell you whether you have the SARS-CoV-2 virus. If you’re infected, they work regardless of whether you have Delta, Omicron, or another known variant.
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👩🏻‍🔬To determine which variant you have, your specimen needs additional analysis, like “sequencing” to read the genetic code of the virus in your body, or specific molecular tests that tease apart variants. Results from these analyses are used by scientists to understand the SARS-CoV-2 virus and to inform public health measures.
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🙏Thanks to Dr. Bronwyn MacInnis, dear friend & genomic pathogen surveillance guru, for input and review.
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💕Cross posted @dear_pandemic
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#fueledbyscience #rapidtest #rapidtestcovid19 #covidtest
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Join me for a whirlwind tour of the world of allergies with Dr. Samira Jeimy, an allergist and clinical immunologist at Western University in Canada.
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In her day job, Dr. Jeimy helps families prevent and manage all sorts of allergies, from drugs and vaccines, to chronic hives, to common food allergens like peanuts, milk, and egg. On the side, she posts science-based tidbits on social media.
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In this episode, we discuss:
✅ The biology of allergies - What's going on inside us and why allergies are on the rise
✅ Prevention and management - There's a lot we can do!
✅ Allergy testing - Clinical testing vs misleading consumer testing (beware!)
✅Myths and misconceptions - Is that really an allergy?!
✅ Awareness - Important for everyone - even without allergies.
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PROTIPS
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👉Be allergy aware and sensitive to others. Roughly 1 in 10 US adults have a food allergy, and nearly half involve severe reactions.
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👉Not all intolerances are allergies. Allergies involve specific immune pathways. It's worth sorting out what you have to guide management (and avoid Dr. Jeimy's wrath when the word allergy is misused!)
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👉Early exposure is key for prevention. This can be done with supervision in some contexts.
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The seminal 2015 "LEAP" randomized controlled trial of peanut allergies is remarkable. Infants who were at high-risk of peanut allergy were far less likely to develop a peanut allergy (at age 5 years) if they were exposed to peanuts as infants, rather than avoiding them. We're talking roughly 3 to 6 times lower rates in those who were exposed, depending on the patient subgroup.
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MORE
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🎧Tune into Ep 37 of Get Real Health with Dr. Chana Davis on your fave podcast platform
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🤩Check out Dr. Samira Jeimy's website and her Insta page at @drsamirajeimy
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STUDIES
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Prevalence and Severity of Food Allergies Among US Adults (Gupta et al, 2019)
DOI: 10.1001/jamanetworkopen.2018.5630
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LEAP Peanut Exposure Trial (Du Toit et al, 2015)
DOI: 10.1056/NEJMoa1414850
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#fueledbyscience #podcast #allergies #foodallergies #nutallergy #allergickids #parenting #allergenfree #allergenfriendly #mastcell
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This book spoke to me. Like many of my friends, I’m often self-critical about my appearance. When I look on the mirror, or at photos, there’s always something I want to “fix”. It’s exhausting - and futile.
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More Than a Body digs into the forces that lead many of us to spend our lives in a self-critical mindset, so that we can begin to break free.
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We need a paradigm shift. It's not our bodies, faces, skin, or hair that needs fixing, it's our culture. Women (especially) are told from an early age that our worth is tied to our appearance. No matter what we accomplish, we'd better look good doing it (with a very narrow definition of "good") . It's a recipe for a lifetime of discontent - and a bountiful beauty industry. 
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📣”Positive body image isn't believing your body looks good, it's knowing your body is good, regardless of how it looks."
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The authors are twin sisters, like my little girls. They describe being washed into "the seas of self-objectification" at an early age, where they monitored and criticized their looks relentlessly. I cringe when I reflect on all the collective wasted emotional energy spent in those seas.
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To support my daughters (almost 6) in loving themselves no matter what, it starts with me, their number one role model. I'm working on it. It’s not easy but I’m committed.
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🔥Hot tip: Be mindful of your media environment - and that of your kids. If your feed is making you feel badly about yourself ...UNFOLLOW!
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💕Who encourages you to value and embrace yourself, independent of how you look? Please share! 👇
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Check out @beauty_redefined for more from the authors, Drs. Lindsay and Lexie Kite. 
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PS Not an ad, I just feel strongly about spreading this important message. This book would be a great gift for yourself or others!
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#fueledbyscience #morethanabody #selflove #womenforwomen #womensupportingwomen #paradigmshift #beautyculture #iweigh #innerbeauty #selfworth #notanad #bookideas #bookreview #bookrecommendations
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