HoldsUp

Luc van Loon

Luc van Loon is a researcher in the fields of exercise science, sports nutrition, and muscle metabolism. His published research focuses on dietary protein requirements, muscle protein synthesis rates, and the metabolic effects of exercise. He also investigates the impacts of amino acid supplementation and resistance training on muscle mass and recovery across diverse populations, including athletes, older adults, and clinical patients.

55 claims checked on air: 2 context 1 contradicted 4 overstated 41 supported 7 unverified

What they said on air - overstated

13 citing their own research

0:45:36overstatedmoderateDr. Luc Van Loon: Optimizing Protein Intake & Distribution f

Performing two sessions of resistance exercise per week prevents the loss of lean mass during a hypocaloric diet.

"we know from all hypocaloric diets that if you actually are are on a hypocaloric diet, that two sessions of resistance exercise throughout the week prevents the lean mass loss." (said at 0:45:36)

While resistance training significantly attenuates the loss of lean mass (fat-free mass) during calorie restriction compared to diet alone, claiming that two weekly sessions completely 'prevents' lean mass loss across 'all hypocaloric diets' overstates the evidence. Meta-analyses demonstrate that exercise substantially reduces the proportion of weight lost as lean tissue (e.g., from ~22% with diet alone down to ~8% with exercise), but does not entirely eliminate lean mass loss under all conditions. Furthermore, lean mass preservation during an energy deficit is strongly dependent on the size of the caloric deficit (with deficits >500 kcal/day substantially impairing lean mass retention), baseline adiposity, dietary protein intake, and training volume.

1:01:38overstatedmoderateDr. Luc Van Loon: Optimizing Protein Intake & Distribution f

Consuming food while sitting upright stimulates gastric emptying, leading to faster circulating amino acid release and greater muscle protein synthesis stimulation compared to eating while lying down.

"We did studies sitting upright or lying down, which is of course very relevant for people in the hospital, because a lot of people are being fed lying down, but sitting upright actually stimulates gastric emptying, so the protein actually gets faster in your digestive system, you get a faster release in circulating amino acids and therefore a greater stimulation of muscle protein synthesis." (said at 1:01:38)

The claim that eating in an upright sitting position accelerates gastric emptying and increases circulating amino acid availability compared to lying down is supported by randomized crossover studies. In 8 healthy young men ingesting 20 g of milk protein, an upright sitting position significantly accelerated gastric emptying (measured via paracetamol kinetics) and increased peak plasma leucine and overall amino acid availability compared to a supine lying position (PMID: 28212491). Similar reductions in gastric emptying and amino acid availability were observed in a head-down tilted position (PMID: 27089362). However, claiming that this posture change causes a "greater stimulation of muscle protein synthesis" overstates the published evidence. The cited trials measured gastrointestinal emptying rates, digestion, and systemic amino acid concentrations, but did not directly measure muscle protein synthesis rates (e.g., via muscle tissue biopsies). While higher amino acid availability is a prerequisite for muscle protein accretion, direct stimulation of muscle protein synthesis was inferred rather than experimentally measured.

1:04:33overstatedhighDr. Luc Van Loon: Optimizing Protein Intake & Distribution f

Consuming 20 grams of protein requires eating about 70 grams of meat, whereas getting 20 grams of protein from potatoes requires eating more than 1 kilogram.

"If you want to ingest 20 grams of protein through eating meat, it's 70 grams of meat. If you want to get 20 grams of protein in by eating potatoes, you have to eat more than a kilogram of potatoes." (said at 1:04:33)

Nutritional analyses establish that lean meat typically contains approximately 20–30 g of protein per 100 g (meaning 70–100 g of meat yields roughly 20 g of protein), whereas raw and cooked whole potatoes contain approximately 2.0–3.1 g of protein per 100 g fresh weight (FW). Consequently, obtaining 20 g of protein from potatoes requires approximately 650 g to 1,000 g of potatoes, rather than 'more than a kilogram.' While the general principle regarding the substantially higher protein density of meat compared to whole potatoes is correct, stating that one must consume over a kilogram of potatoes overstates the required amount.

1:33:28overstatedhightheir own paperDr. Luc Van Loon: Optimizing Protein Intake & Distribution f

The adverse muscular side effects of androgen deprivation therapy (ADT) in prostate cancer patients can be fully overcome with resistance exercise, allowing patients to increase muscle mass and strength.

"The ADT is life-saving, but then all the negative effects of the ADT can be completely, fully overcome with resistance exercise." (said at 1:33:28)

Randomized controlled trials and meta-analyses show that resistance exercise effectively counteracts muscle loss, increases muscle strength, and improves physical function in prostate cancer patients undergoing androgen deprivation therapy (ADT). However, stating that resistance exercise can "completely, fully overcome" "all the negative effects of the ADT" overstates the evidence. While resistance exercise attenuates or prevents the loss of lean mass during ADT, hypertrophic gains are blunted compared to healthy age-matched individuals without testosterone suppression. Furthermore, ADT induces wide-ranging systemic side effects—including bone mineral density loss, metabolic changes, hot flashes, fatigue, and sexual dysfunction—that resistance exercise alone does not completely eliminate.

Fact-checked episodes

Publications