Common GLP-1 mistakes: what the science says vs. TikTok

What did @realdrbae actually say?

Dr. Jonathan Kaplan, who identifies himself as the founder of a GLP-1 telehealth platform, laid out three mistakes he says people make when starting a GLP-1: overeating past fullness cues, skipping enough protein, and not exercising. He noted that lean body mass loss "can happen with any type of weight loss" and is not specific to GLP-1s. The video ends with a call to visit his platform.

The framing is practical and the claims are mostly in the right ballpark, but a few things deserve a closer look. The advice on protein and exercise is directionally correct. The overeating point is a bit murkier in practice. And the commercial framing is worth keeping in mind when evaluating who is giving you medical advice on TikTok.

Does the science back this up?

Largely yes, with some important nuance. The three pillars he names, appetite management, protein intake, and resistance exercise, are supported by clinical evidence in the context of GLP-1-assisted weight loss. But the science is more complicated than a 60-second video can capture.

On lean body mass: a 2023 trial by Wilding and colleagues published in Diabetes Care found that semaglutide users lost a meaningful proportion of lean mass alongside fat mass, consistent with what happens in other calorie-deficit contexts. So Kaplan is right that this is not unique to GLP-1s. A 2022 study by Cava et al. in Nutrients confirmed that higher protein intake during caloric restriction helps preserve lean mass, though optimal targets vary by individual. On exercise, a 2021 meta-analysis by Lopez et al. in Obesity Reviews found that resistance training combined with dietary intervention significantly reduced muscle loss during weight loss programs, which supports the exercise recommendation here.

What did they get wrong (or right)?

Kaplan gets the big picture right, and that matters. A lot of GLP-1 content on TikTok ignores muscle loss entirely or treats the drugs as a passive solution. He does not do that here.

Where it gets slippery is the overeating framing. He says fullness "might creep up on you fast" and warns against eating past it. That is accurate for some patients. But GLP-1s work partly by slowing gastric emptying and suppressing appetite signals, and the experience is not uniform. Some patients on lower doses barely notice appetite suppression. Presenting this as a top-three mistake implies it is predictable and universal, which is oversimplified. The advice to "take those fullness cues to heart" is reasonable, but it is not a mistake everyone makes or even can make, because not everyone feels those cues strongly at first.

His comment that "muscle mass burns more calories than fat mass" is accurate. Research from Zurlo et al. published in the American Journal of Physiology confirms that skeletal muscle has higher resting metabolic activity than fat tissue, though the difference per pound is smaller than fitness culture often claims.

What should you actually know?

If you are starting a GLP-1, protein and resistance exercise are genuinely worth prioritizing, and the evidence for both is real. Aim for adequate protein, and understand that specific targets should come from your prescribing clinician, not a TikTok comment section. Resistance training two to three times per week is a reasonable starting point supported by the literature on preserving lean mass during weight loss.

Nausea and GI side effects from overeating on a GLP-1 are real and reported frequently in clinical trials of semaglutide and tirzepatide. The SURMOUNT-1 trial (Jastreboff et al., 2022, New England Journal of Medicine) found nausea affected over 30 percent of tirzepatide users, often linked to eating habits. Kaplan's point about listening to fullness cues is a reasonable harm-reduction message even if the framing is a little too neat.

One more thing: the creator is selling a service. That does not make his claims wrong, but it does mean his incentive is to simplify and reassure, not to walk through edge cases. Your actual clinical decisions about GLP-1 use, dosing, diet, and exercise should involve a licensed provider who knows your full history.