Bulking up is a hot topic in our house. Getting big. Getting muscles.
The owner of this obsession is my 15-year-old son. "Do you think I want to be skinny all my life?" he asks.
Being wiry is not a moral failing, I say. And even if I were to stop feeding him, he would grow the next few years on a scavenged diet of chips and bikkies. Like a weed in a footpath, the miracle continues.
Patience is not Master 15's jam. Like many teenaged boys, he wants defined pectoral and abdominal muscles yesterday. Big biceps, too.
He and his mates have turned to protein powder. It's a concoction of whey or soy protein blend, thickeners and flavourings. You can find vegan versions, chocolate versions, even flavoured varieties like cake doughnut and key lime pie. One kilogram of the stuff can cost $90. Some brands have heaps of sugar, hidden contaminants and trans fats.
Web MD says getting extra protein can be helpful for growing bodies (teenagers) and those starting a workout programme.
But dietician and sports nutritionist Barbara Lewin is quoted saying to build a pound of muscle (about half a kilogram), the body needs about 10 to 14 additional grams of protein each day.
"That's not really that much. Some of these powders have 80 grams of protein per serving. You don't need that. All your body is going to do is break it down for energy. And too much protein can be hard on your kidneys and your liver."
When it comes to teens, The Academy of Nutrition and Dietetics (US) cautions against using protein supplements, saying they can also contribute to dehydration. The academy recommends teenagers get protein from foods.
I make my case to Master 15, telling him a can of tuna, chickpeas, a chicken breast or a couple of eggs are a lot cheaper and probably better for him than a pricey tin of fake food.
He's not having it. He informs me, "I've done my research. I found information on Google. My friends have done even more research than me."
That settles it. My son and his mates are now experts on supplements and human physiology. I've no idea why they bother continuing their education, since they know so much already and could probably start their own sports medicine and nutrition consulting firm.
I don't buy the powder. If Master 15 wants to spend his allowance contributing to the yacht payments of whoever owns the supplement company, that's his choice.
What's happening in our house is a microcosm of what's been evolving in the world for years. Many of us believe reading articles online and watching videos is equivalent to expertise.
I'm guilty of using the web as a proxy for a person with experience and knowledge. It's a shortcut to a place we can't be bothered spending time or money.
It's the doctor's visit you'd rather skip, or the home improvement tutorial that might save hundreds of dollars - or cost extra if you botch the job.
Covid-19 has raised the stakes in our DIY world. Amateur epidemiologists and armchair scientists have convinced themselves of their own expertise.
It's the Dunning-Kruger effect in action: a cognitive bias where people believe they are smarter and more capable than they really are. We can't recognise our own lack of ability. In other words, we don't know what we don't know.
When, for example, Covid skeptics or anti-vaxxers say they've "done their research", what they're saying is they know more than doctors who have spent thousands of hours studying medicine, or they know more than professional scientists who've spent thousands of hours in a laboratory. Why does anyone need medical school when we have the internet?
However, I don't want my surgeon slicing into my gut or brain if her/his training consisted mostly of watching YouTube videos. I'm also not taking advice about vaccinations from someone whose main method of persuasion is sharing conspiracy theories.
Many of us have healthy suspicions about doctors based on years of personal experience. An individual doc may flub a diagnosis or fail to offer the right medicines to relieve symptoms.
That doesn't render the entire profession obsolete. Academics and expertise still matter. When a Covid-19 vaccine is finally offered to the general public in Aotearoa, people who value expertise can seek credentialed experts for advice.
I don't suspect I'll win the protein powder argument. Peer pressure is strong. And muscle gains - due to extra gym sessions, extra protein, or both, will perpetuate the cycle. But when it comes to weightier matters - those of life and death - Dr Google will not have the last word.