Two Cenegenics coaches with 25 combined years of experience separate protein science from protein marketing, and explain what to do instead.
Walk down any grocery aisle and you’ll find protein chips, protein cereal, protein water and protein mac and cheese. Social media has made protein the most celebrated nutrient of the decade.
“Protein has the best publicist known to man right now,” says Marcos Rivera, a performance health coach at Cenegenics Las Vegas who has coached members for eight years. “It’s in everything.”
The hype isn’t wrong about protein mattering. But it has buried the basics under products, timing rules and slogans. Erik, Vice President of Clinical Operations at Cenegenics, sat down with Marcos and Rudy, Senior Vice President of Performance Health, now in his eighteenth year with Cenegenics. The goal was to sort out what actually moves the needle.
Why protein matters more as you age
The biggest reason is muscle. “For most people our age, a little younger, and definitely older, it’s a war of attrition with muscle mass,” Rudy says. “We are constantly at risk of losing muscle as we get older.”
Protein can’t win that war alone. “You need to stimulate that muscle with mechanical tension, and that’s resistance training,” Rudy adds. Protein also supports recovery and immune function, and it is the most energy-costly macronutrient to digest. Roughly 20 to 30 percent of the calories in protein are spent processing it, compared with about 5 to 10 percent for carbohydrates and 0 to 3 percent for fat (Westerterp, 2004).
The GLP-1 blind spot
The stakes are higher for the growing number of people using GLP-1 medications to lose weight. Marcos says protein “tends to be missed by most people” on these therapies, because appetite drops and meals shrink.
That matters because not all weight lost is fat. In the STEP 1 semaglutide trial, roughly 39 percent of the weight participants lost in a body-composition substudy was lean mass, as measured by DEXA (Wilding et al., NEJM 2021). Lean mass on a scan includes water and organ tissue, not just muscle. Still, the takeaway for anyone on these drugs is simple: protect muscle on purpose, with adequate protein and resistance training.
How much you need: start with a measurement, not a slogan
Online debates about “one gram per pound” usually skip a key question: per pound of what? At Cenegenics, every member’s evaluation includes a DEXA scan, which measures lean tissue directly. “It gives us a firm stance to plant,” Marcos says. The coaches use one gram of protein per pound of lean tissue as a baseline goal, then adjust it.
For context, an international expert group (PROT-AGE) recommends that adults over 65 eat at least 1.0 to 1.2 grams per kilogram of body weight daily to maintain muscle and function (Bauer et al., 2013). The Cenegenics baseline is a coaching target built on measured lean mass, not a universal rule.
It’s also a range, not a bullseye. “It might be plus or minus 10 percent,” Marcos says. “We don’t need to be pinpoint precise.”
The tool you always have with you
Most people have no idea what 25 grams of protein looks like. So Marcos teaches the hand method. A cooked portion about the size of your palm is roughly 25 grams of protein. Someone with 150 pounds of lean tissue would aim for about six palm-sized portions a day.
“It’s not the most precise tool,” he says. “But it gets them into the habit of paying attention.” It also works at a business dinner, where no executive is pulling out a food scale. A six-ounce fillet, weighed raw, comes out of the kitchen at about the size of your palm.
Hunger is the feedback loop. If a larger person is starving 90 minutes after a palm-sized portion, Rudy has them go bigger, “to that first knuckle, or maybe the second knuckle.” His target for most people building good habits is a little hunger around the three- to four-hour mark.
Read the label like a coach
Some “protein foods” are mostly something else. Peanut butter and nuts are primarily fat. Even a whole egg, a genuinely good food, gets only about a third of its calories from protein: roughly 6 grams of protein and 5 grams of fat (USDA data via FatSecret).
Rudy’s grocery-store rule of thumb: if a protein’s total fat per serving is a single digit, it can count as a leaner choice. That way a normal six- or eight-ounce portion doesn’t bring a pile of fat calories you didn’t plan for.
The same logic applies to powders. A true protein powder has roughly 25 to 30 grams of protein with under 3 grams of fat and only a few grams of carbohydrate. Ten grams of fat and 30 grams of carbs per scoop make it a meal replacement. That’s not bad, but blending it with oats, berries and nut butter can quietly add 300 to 400 calories a day. “If they’re doing that every day, they could have some unintended weight gain, or just stalled weight loss,” Rudy says.
Timing matters less than you’ve been told
Six small meals a day. A shake within 30 minutes of lifting. No more than 40 grams per meal. Most of these rules overstate a small effect.
“Your protein total for the day resets every day,” Marcos says. “That amount is the daily driver.” How you get there can change with your schedule.
The per-meal ceiling is also weaker than gym lore suggests. A 2023 study found that 100 grams of protein after exercise produced a larger and longer-lasting muscle-building response than 25 grams, lasting more than 12 hours (Trommelen et al., Cell Reports Medicine). Marcos has a theory about the old 40-gram figure: “It was convenient that the maximum dose was also equivalent to two scoops of protein powder.”
Rudy, who has lifted for more than 25 years, agrees that the post-workout shake is optional for people who eat protein consistently. “It’s not going to stall you from building lean tissue if you’re just relying on your meal source.”
The exception is the opposite problem. Some members arrive after a year of one-meal-a-day intermittent fasting, eating perhaps 40 grams of protein daily against a need closer to 150. For them, the coaches might break the fast with a shake and follow it with a full meal about 90 minutes later, so the daily target feels achievable.
Real food first: the protein hierarchy
Cenegenics coaches rank protein sources roughly like this:
- Whole food: meat, fish, eggs, dairy.
- Protein shakes: useful supplements, as the name says.
- Whole-food bars with a short ingredient list.
- Candy-style protein bars.
- Amino acid powders.
“If you need a bar or a shake, those things are supplemental. That’s literally in the name,” Marcos says. He aims for 80 to 90 percent of food to be “real things.” Rudy calls the protein-fortified chips and cereals “Frankenfoods”: foods altered to chase a market trend.
Bars have a place: an airplane, or a hockey rink in the northern Midwest with no restaurant in sight. But Rudy warns about sugar alcohols. “The things that taste like a candy bar” often bring bloating, gas and irregular digestion. “If I have eight ounces of cooked beef and vegetables sitting in the fridge and I’m choosing to eat these bars, that’s not the right decision.”
Protein is a building block, not fuel
The newest mistake is eating so much protein that there’s no room left for energy. “Protein is a terrible energy source,” Marcos says. “If you’re looking for energy to get you through a day, do not go with protein as the main thing.” Your body can convert protein to glucose, but it’s an inefficient pathway. Taken to the extreme, a diet of almost nothing but lean protein can cause a dangerous condition known as “rabbit starvation.”
The remaining calories should match how you live. An avid athlete might lean on carbohydrates. A more sedentary executive might rely more on slower-burning fats.
Rudy learned this the hard way. In his early twenties, chasing a bodybuilding coach’s per-meal protein target, he discovered that a whole frozen pizza hit the number exactly. “I just got fat,” he says. “People can hone in on one thing through a really concentrated lens and think it’s the right thing. But you’ve got to look at the whole picture.”
The bottom line
Protein deserves its reputation. But the essentials are less exciting than the marketing:
- Know your target, ideally from a measured lean mass.
- Hit it most days, mostly from whole food.
- Pair it with resistance training.
- Leave room for the fuel your day demands.
The details are where people get lost. “There’s so much information that can feel contradictory,” Rudy says. “You feel like you’re in the middle of the ocean without a paddle.” That’s why every Cenegenics member works with both a physician and a coach. Together they measure, adjust and follow up, so the plan fits the person rather than the trend.
