How to stay lean as you age
Written by Martin Ebner
Updated Sept 2026
Getting older doesn’t automatically make you heavier. It does make the habits you got away with in your twenties a little less forgiving.
I’m 42 now. I train three times a week, I’ve been lifting for more than 25 years and I don’t stay lean by trying to live like I’m 22. I keep the useful bits in place: strength training, plenty of movement, enough protein and food portions that match the life I’m actually living.
The encouraging part is that your metabolism probably hasn’t collapsed. What usually changes is the amount you move, the muscle you carry, the way you eat and how consistently you recover. Those are all things you can work with.
YOUR METABOLISM HASN’T FALLEN OFF A CLIFF
The old story says your metabolism starts slowing dramatically in your thirties and weight gain becomes almost inevitable. The evidence is far less depressing. A large study of daily energy expenditure found that, once body size and composition were accounted for, metabolism remained broadly stable from the age of 20 to 60. The average decline started later.
That doesn’t mean your body and life stay exactly the same. A busier job can mean more sitting. Family commitments can squeeze out training. Sleep can become less predictable, and a little less movement combined with slightly larger portions can add up over several years.
For women, the menopause transition can also change body composition and shift more fat towards the abdomen. That’s a real physiological change, not a failure of discipline. The practical work still includes strength, movement and nutrition, but sudden or substantial changes are worth discussing with a doctor rather than quietly blaming your age.
The answer isn’t to blame your age. It’s to look honestly at what has changed and adjust the parts that matter.
KEEP LIFTING
If staying lean is the goal, strength training deserves a permanent place in your week. It helps you maintain or build muscle, keeps you physically capable and gives the weight you lose a better chance of coming from fat rather than useful tissue.
I’m not going to tell you that adding a few kilos of muscle turns your metabolism into a furnace. It doesn’t. The more important point is that muscle gives your body shape, strength and resilience. Losing weight while becoming weaker isn’t much of a result.
Two or three properly planned sessions a week can do an enormous amount. You don’t need to train every day, and you certainly don’t need to destroy yourself. You need a program that covers the main movement patterns, progresses over time and fits well enough into your life that you’ll still be following it next year.
If fat loss is your main goal, I’ve explained more about why strength training belongs in the plan.
DON’T LET DAILY MOVEMENT DISAPPEAR
Training matters, but so does everything you do outside the gym. A few workouts can’t completely compensate for spending the rest of the week almost motionless.
Walking is the obvious place to start because it’s easy to recover from and doesn’t need to feel like another workout. Walk to do something rather than pacing around the living room to satisfy a watch. Take the longer route, get off the bus earlier, go out after dinner or arrange to meet someone on foot.
You don’t need one magical step target. You need enough daily movement that your active life hasn’t quietly become a seated one.
EAT FOR THE LIFE YOU HAVE NOW
There’s no sensible rule saying you should remove 200 calories for every decade after 30. Your needs depend on your body size, activity, goals and health, not the year on your birth certificate.
What I usually find is that portions have crept up while movement has crept down. Nobody notices either change because both happen gradually. Start by looking at what you regularly eat, how often you snack, what you drink and whether the weekend has quietly expanded into Thursday night.
You don’t need to make every meal tiny. Build most of them around protein, fruit or vegetables and food that actually satisfies you, then leave room for the things you enjoy. Fuel first, pleasure second. Both belong.
If your average weight and waist measurement are rising for several weeks and that isn’t what you want, make one modest adjustment. You can always review it. There’s no prize for making the diet as miserable as possible.
PROTEIN BECOMES MORE USEFUL, NOT MORE EXCITING
Protein helps maintain and build muscle, particularly when it’s paired with resistance training. For many healthy, active adults, roughly 1.2 to 1.6 grams per kilo of body weight each day is a useful range. At 80 kilos, that works out at roughly 96 to 128 grams.
You don’t need to hit the number perfectly, and you don’t need to eat chicken six times a day. Spread protein across your meals and use foods you genuinely like. Meat, fish, eggs, dairy, tofu, tempeh and legumes can all contribute. A protein powder is convenient if food alone leaves a gap, but it isn’t superior to food and it isn’t compulsory.
There’s more detail in my guide to how much protein you need for your fitness goals. The research on resistance training suggests that benefits tend to level off around 1.6 grams per kilo per day for most people, so more isn’t automatically better.
CARDIO DOESN’T NEED A TRICK
You don’t need to do cardio fasted, find a special fat-burning heart-rate zone or sweat in several layers. Fasted exercise can increase the proportion of fat used during that particular session, but the available evidence doesn’t show a meaningful long-term fat-loss advantage when the rest of the diet is comparable.
If you like walking or training before breakfast and you feel good doing it, carry on. If you perform better after eating, eat. The best time is the one that lets you train well and repeat it.
Use cardio to improve your fitness, increase your weekly activity and do something you enjoy. Brisk walking, cycling, swimming, running and intervals can all work. If strength matters to you too, my guide to combining cardio and weights will help you organise them without making every session a compromise.
WEIGHT-LOSS DRUGS HAVE CHANGED THE CONVERSATION
Prescription medicines such as semaglutide and tirzepatide can produce substantial weight loss in people for whom they’re clinically appropriate. In the STEP 1 trial, people taking semaglutide alongside lifestyle support lost an average of 14.9% of their body weight over 68 weeks, compared with 2.4% in the placebo group. That isn’t a marginal effect, and pretending these drugs don’t work doesn’t help anyone.
I don’t consider using effective medication to be cheating. I also don’t consider it magic. These are prescription drugs, not supplements, and decisions about eligibility, side effects, dose and long-term use belong with a qualified clinician.
The plan around the medication still matters. A follow-up to the semaglutide trial found that participants regained around two-thirds of their previous weight loss in the year after treatment stopped. That isn’t an argument against taking it. It’s a reason to discuss what maintenance might look like before treating the medication as a short course with a neat finish line.
Rapid weight loss can also include some lean tissue, whatever method produces it. If a drug has dramatically reduced your appetite, getting enough protein and continuing to lift become more important, not less. Current clinical guidance emphasises resistance training, adequate nutrition and monitoring strength and function during treatment. The scale is only one part of the result.
SLEEP STILL COUNTS
Sleep isn’t a fat burner, but poor sleep can make every part of the plan harder. Hunger is more difficult to manage, training feels heavier and good decisions require more effort when you’re exhausted.
In a controlled weight-loss study, moderate sleep restriction changed the quality of the weight participants lost, with a smaller proportion coming from fat despite similar overall weight loss. You can’t always control how long you sleep, but you can give it a better chance by protecting a regular bedtime, reducing late-night work where possible and not treating recovery as time wasted.
TRACK THE TREND, NOT YOUR YOUNGER SELF
Your body weight can move from one morning to the next because of water, salt, carbohydrates, digestion and dozens of other ordinary things. Judge the trend over several weeks instead.
Use a weekly weight average if the scale is helpful, measure your waist once a month and keep a record of your training. Clothes, photographs, energy and strength can add context. If your waist is coming down and your lifts are holding steady, that tells you far more than one dramatic weigh-in.
Most importantly, stop using your 22-year-old body as the standard. The goal isn’t to rewind your life. It’s to be lean, strong and capable in the body you have now.
AGE CHANGES THE CONTEXT, NOT THE JOB
Staying lean as you age still comes down to a few useful things done consistently. Keep your muscle, keep moving, eat an amount that matches your life, recover properly and use medical support when it’s genuinely appropriate.
I’ve coached people through every version of this for 15 years. The details change, but the principle doesn’t. I’d rather build a decent plan you can follow than hand you a supposedly perfect one that lasts a fortnight.
If you’re in Barcelona and want some structure around training, food and sustainable fat loss, you can read about weight-loss coaching with me.
If you’d rather get useful fitness advice without another stranger shouting about cortisol, morning routines or the food you’re apparently never allowed to eat again, Check It Oot is my newsletter. I send it once or twice a month, when I’ve got something worth saying.
