Losing weight in your 40s and beyond isn’t the same as it was in your 20s or 30s. Even if you’re eating well and exercising regularly, your body responds differently due to natural age related changes but we don’t think you need to pay for it!
The UK has seen over 500,000 starting weight loss drugs and around 95% are paying for them privately (WeightMatters, 2025). A recent poll found that 1 in 5 would start weight loss drugs if they were available on the NHS (Campbell, 2024).
Boots UK charges £199 per month for weight loss drugs (online doctor.boots.com, n.d.), that’s £2,388 a year!
The good news is with a few small changes healthy weight loss is achievable and sustainable! In this blog post we will better understand our bodies and how to fuel them in the right ways. This means you don’t need to spend thousands on weight loss!
Why is weight loss harder after 40?
Here’s three reasons why losing weight becomes more difficult and what you can do about it!
1. Slower Metabolism (The “Metabolic Slowdown”)
What happens: Your basal metabolic rate (BMR), the calories your body burns while resting, declines by about 1–2% per decade after age 30 (www.fao.org, n.d.). This is due to muscle loss (sarcopenia) and reduced cellular activity.
The impact: You burn fewer calories doing the same activities, meaning old eating habits now lead to weight gain.
The Solution:
- Strength training to preserve muscle, this can maintain your BMR.
- Higher protein intake to combat muscle loss.
- Avoid drastic calorie cuts, which further slow metabolism.
2. Hormonal Shifts
For women (Perimenopause & Menopause):
Women often see a decline in Estrogen which leads to increased belly fat storage and harder to lose weight. As well as a rise in Cortisol (stress hormone) sensitivity, making stress related weight gain more likely (Health, 2024) .
For men:
Is it common for Testosterone to drop gradually in men which reduces muscle mass and increases fat storage. Also Insulin resistance becomes more common making carbs harder to process (Krans, 2018).
The Solution:
- Prioritize sleep (7–9 hours) to regulate hunger hormones (ghrelin & leptin).
- Manage stress with mindfulness, walking, or resistance training.
- Focus on fibre & healthy fats to balance blood sugar.
3. Busy Lifestyles (Less Time, More Stress)
Career, family, and responsibilities leave little energy for meal prep or exercise coupled with convenience foods becoming quick and easy options, it is common to gain weight once we hit 40.
Solution:
- Batch cook simple meals for the week
- Fit exercise during work! Walk while on calls, take stairs, park farther away.
- Short and efficient workouts lasting 20-30 can fit in exercise while keeping it enjoyable
Did you know that people eating home cooked meals more than five times a week were 28% less likely to be overweight (BBC, 2024).
Understanding Your Calorie Needs
Why it matters: Weight loss still hinges on calories in vs calories out, even though our bodies have changed.
Understanding what your body burns at complete rest just to keep your heart, brain, and organs functioning ensures you are keeping your body and mind healthy!
Using the Mifflin-St Jeor Equation is best for this as it is the most accurate for adults over 40. The equation differs slightly for men and women, but it is straightforward.
Step 1: Calculate your BMR
For Men:
(10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5 = BMR
For Women:
(10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161 = BMR
Example:
50-year-old woman, 170 lbs (77 kg), 5’6” (168 cm)
BMR = (10 × 77) + (6.25 × 168) – (5 × 50) – 161
BMR = 770 + 1,050 – 250 – 161 = 1,409 kcal/day
Step 2: Adjust for Activity Level (TDEE)
Multiply your BMR by an activity factor to get your Total Daily Energy Expenditure (TDEE) the additional calories you burn in a day.
| Activity Level | Multiplier | Description |
| Sedentary | X 1.2 | Little/no exercise, desk job |
| Lightly Active | X 1.375 | Light exercise 1–3 days/week |
| Moderately Active | X 1.55 | Moderate exercise 3–5 days/week |
| Very Active | X 1.725 | Hard exercise 6–7 days/week |
| Athlete | X 1.9 | Physical job + intense training |
Example (Same Woman, Lightly Active):
1,409 (BMR) × 1.375 = 1,937 kcal/day – These would be her maintenance calories, the amount required to maintain her current weight.
Step 3: Determine Your Weight Loss Calories
The final step is to reduce your maintenance calories to start losing weight. A modest deficit, 300–500 kcal/day, is recommended as it leads to 1–2 lbs of fat loss per week (Hennessy, 2023).
This level of weight loss is sustainable, aggressive deficits, 500 kcal or above, risk muscle loss, metabolic slowdown, and rebound hunger, this is likely to lead to weight gain over losing weight!
There are many free tools for calculating BMR, we would recommend this one
Volume Eating: To Feel Full While Losing Weight
Why it matters: Hunger is a major reason people quit diets. Volume eating is filling up on low calorie, high fibre, high water foods (like veggies, fruits, and lean proteins) to feel full while consuming fewer calories. This helps you eat more and reduces your hunger while losing weight.
Best foods for volume eating:
- Non-starchy veggies (spinach, broccoli, zucchini)
- Lean proteins (chicken breast, fish, tofu)
- High fibre foods (berries, legumes, oats)
Move More: Exercise for Weight Loss & Health
Why it matters: Exercise preserves muscle, boosts metabolism, and improves insulin sensitivity all are key for weight loss past 40!
We want to focus on sustainable exercise, ensuring you can fit it into your week is vital. The key is to focus on low impact exercise such as walking, swimming or cycling. Starting fitness classes can be too intensive causing injuries or reducing enjoyment as well as increasing hunger.
The key for sustainable change is consistency small, daily habits matter more than occasional intense workouts.
Conclusion
Losing weight after 40 may come with challenges, but it’s entirely achievable with the right approach and without the costly weight loss drugs.
By understanding your changing metabolism, adding some light exercise, being aware of your calories and adopting practical strategies like volume eating you can achieve sustainable results while saving £199 a month!
Remember, small, daily habits like batch cooking or short workouts, add up over time. Avoid drastic measures; instead, focus on gradual progress that supports long term health.
Ready to take the next step? Start by calculating your BMR today and make one small change this week, whether it’s adding more veggies to your plate or a 20-minute walk.
Share your weight loss tips and tricks in the comments below!