Does eating once a day build muscle after 50? A look at the claims, the evidence, and what to do instead.
You’ve probably heard the story: Tibetan monks in their 50s, one meal a day, still strong. It makes a good story, but we couldn’t find a single study measuring muscle in monks who eat once a day, so we won’t pretend it’s proven.
What the research says about eating once a day
In a small controlled trial, normal-weight, middle-aged adults ate in one evening meal for eight weeks, then in three meals for eight weeks. On one meal they lost slightly more weight and fat, but their total and LDL cholesterol and blood pressure went up. The group was small and the periods short, so treat it as a caution, not a verdict.
Fasting does raise growth hormone. In six men who fasted for five days, 24-hour growth hormone output roughly tripled. That was a five-day fast, though, and the study measured hormones, not muscle. It’s no reason to skip meals.
What matters more for muscle: total protein
Timing gets a lot of attention, but a meta-analysis of protein timing found that once you account for how much protein people ate, timing made no significant difference to hypertrophy (muscle growth). Total protein intake was the strongest predictor. A systematic review of time-restricted eating in active people reached a similar conclusion: when calories and protein matched, lean mass results were similar to a normal diet.
Your daily protein matters more than how short your eating window is.
Key takeaway: Eating once a day isn’t a muscle-building trick. Hit your daily protein and train, however you schedule meals.
How much protein after 50
The PROT-AGE expert group recommends at least 1.0 to 1.2 g of protein per kg of body weight a day for adults over 65, and at least 1.2 g/kg if you exercise. That’s for people over 65, so treat it as a sensible reference point if you’re in your 50s and lifting. Anyone with kidney disease should talk to a clinician first.
On one meal, you’d eat nearly all of that at once. For an 80 kg person at 1.2 g/kg, that’s about 96 g in a sitting. A single dose of protein needs roughly 0.40 g/kg to maximally stimulate muscle protein synthesis in older adults, so one big meal can clear that bar. A trial in adults aged 65 to 80 also found that even and lopsided protein distribution gave the same muscle protein synthesis when total intake was high (1.5 g per kg of lean mass). The catch: that trial still used three meals, not one.
Putting it into practice
- Skip the monk routine. Aim for 3 to 4 protein-containing meals if you can, so you reach your target without a giant dinner.
- Build each meal around protein, such as eggs, fish, chicken, Greek yogurt or tofu.
- Lift 2 to 3 times a week. Protein supports training and doesn’t replace it.
- Check with your doctor before trying one meal a day, especially with blood pressure, cholesterol or blood sugar concerns.
Proteinly can help with the habit part. It’s a protein-first app with no calorie counting, and its automatic eating timer reminds you to eat every 2 hours, so regular protein becomes routine. We don’t claim it builds muscle faster. Our piece on protein needs after 40 covers per-meal doses in more depth.
Frequently asked questions
Can you build muscle eating once a day?
Possibly, if you train and eat enough protein, but we found no trial showing it works better than regular meals. The one controlled trial we found showed worse cholesterol and blood pressure.
Is there a post-workout window you have to hit?
The protein timing meta-analysis found no significant timing effect once protein totals were matched. Total daily protein matters more.
Do fasting hormones help muscle?
Fasting raises growth hormone, but that evidence comes from a five-day fast in six men and doesn’t show muscle gain.
Next steps
The monk story is more myth than science. After 50, aim for steady protein, regular lifting and meals you can stick with. Build the habit with Proteinly, learn more about our approach, and find us on YouTube.