Losing Fat Over 40: What Changes and What Doesn't

What does change after 40

You lose muscle unless you train for it

A 2004 review by Volpi and colleagues estimated that muscle mass falls by about 3 to 8% per decade after the age of 30, and faster after 60. Less muscle means a little less energy burned, less strength and, on a diet, less to protect.

The good news is that muscle still responds to training. A 2011 meta-analysis by Peterson and colleagues (Medicine & Science in Sports & Exercise) pooled 49 studies of adults with an average age of 50 or more. After about 20 weeks of resistance training, they gained on average about 1.1 kg (2.4 lb) of lean mass. Building muscle after 40 covers how to train for it.

Daily movement often drops

Desk jobs, driving, long commutes and family life can add up to a lot of sitting. If metabolism is not the main cause of midlife weight gain, how much we eat and move are the obvious candidates. The UK Chief Medical Officers advise adults to build up at least 150 minutes of moderate activity a week, to do muscle-strengthening activity at least twice a week, and to break up long periods of sitting.

Sleep can get harder

The NHS lists trouble getting to sleep or staying asleep among common symptoms of perimenopause and menopause, and night sweats can make it worse. Short sleep matters for fat loss: in a small two-week study by Nedeltcheva and colleagues (2010), dieters who slept 5.5 hours rather than 8.5 lost similar weight, but much less of it was fat. Sleep and muscle growth covers how to improve it.

Hormones shift, more for women than men

Men: the NHS says testosterone falls steadily, by about 1% a year, from around the age of 30 or 40, and that this decline is unlikely to cause problems in itself. If you have symptoms such as low sex drive, low mood or fatigue, see your GP rather than guessing at the cause.

Women: the NHS says menopause usually happens between 45 and 55, and that weight gain during perimenopause and menopause is common, often around the stomach and upper body. The SWAN study (Greendale and colleagues, 2019, JCI Insight), which followed women through the menopause with body scans, found that the rate of fat gain roughly doubled at the start of the transition and lean mass began to fall. Both levelled off about two years after the final period.

So the changes around the menopause are real, and worth planning for. If you have symptoms, the NHS advises seeing your GP to talk through your options, including treatment. That is a conversation for your doctor; this article does not give advice on medicines.

Losing fat over 40: a plan that works

1. Lift weights two to four times a week

If you do not already lift, this is the biggest change you can make. It is what keeps the muscle you have, and builds more. Focus on the big movements (squats or leg presses, hip hinges, presses, rows and pull-downs), work close to failure on your working sets, and add weight or reps over time. If you have an injury or a health condition, speak to your doctor or a physiotherapist first.

2. Eat more protein, and spread it out

A 2018 meta-analysis by Morton and colleagues found that the benefit of protein for muscle levels off at around 1.6 g per kg of body weight a day, with 2.2 g/kg covering most people. On a diet, aim toward the top.

How you spread it matters more with age. In a 2015 study by Moore and colleagues, men around 71 years old needed about 0.40 g of protein per kg of body weight in a meal to get the full muscle-building response, against 0.24 g/kg for men around 22. Most readers over 40 are younger than that, but it is a good reason not to skimp. For an 80 kg (176 lb) person, that is about 32 g of protein at each main meal. How much protein to build muscle has food ideas.

3. Keep the deficit moderate

Aim to lose about 0.5 to 1% of your body weight a week, as Helms and colleagues recommend for keeping muscle. The NHS suggests 0.5 to 1 kg (1 to 2 lb) a week for weight loss in general. Crash diets cost muscle, and after 40 you have less to spare.

4. Set a daily step target

Walking is easy to recover from and does not interfere with your lifting. Pick a daily target a little above what you do now, hit it every day, and keep it steady while you adjust your food.

5. Treat sleep as part of the plan

The American Academy of Sleep Medicine recommends at least 7 hours a night for adults. Keep a regular bedtime, a dark and cool room and an earlier caffeine cut-off. If night sweats or hot flushes are wrecking your sleep, that is worth raising with your GP.

6. Judge progress over weeks, not days

Weigh yourself each morning and compare weekly averages. Women who still have periods may see a predictable rise at certain points in the cycle, so compare like with like. Measure your waist too: NICE advises keeping it to less than half your height.

What doesn't change after 40

• Energy balance still decides. Eat less than you burn and you lose weight, at 25 or 55.
• Muscle still responds to training, as the Peterson meta-analysis shows.
• Consistency still beats intensity. A plan you can follow for months will beat a perfect one you drop in three weeks.

How coaching helps

After 40, the plan has to fit your life: work, family, old injuries and, for many women, the menopause. With one-to-one coaching from CoachAk, your training program is written around your schedule, experience, equipment and injury history, and your calorie, macro and step targets are set in a private app and updated as your body responds. Each weekly check-in covers your weight, training and nutrition adherence, steps, sleep, energy, hunger, stress and body measurements, and your coach replies with written feedback on what changes next week and why. You can message your coach directly between check-ins, and send form-check videos for feedback on your lifts.

If you want a plan built for the body you have now, apply for coaching.