Weight loss clears out aging cells and boosts lipid recycling, study finds

Medical Xpress / UK Research and Innovation / Nature ^ | July 9, 2025 | William Scott et al

[ConservativeMind]

Scientists have produced the first detailed characterization of the changes that weight loss causes in human fat tissue by analyzing hundreds of thousands of cells. They found a range of positive effects, including clearing out of damaged, aging cells, and increased metabolism of harmful fats.

The study compared samples of fat tissue from healthy weight individuals with samples from people with severe obesity (BMI over 35) undergoing bariatric weight loss surgery.

The weight loss group had fat samples taken during surgery and more than five months after surgery, at which point they had lost an average of 25 kg.

The researchers analyzed gene expression in more than 170,000 cells that made up the fat tissue samples, from 70 people.

They unexpectedly found that weight loss triggers the breakdown and recycling of fats called lipids. This recycling process could be responsible for burning energy and reversing the harmful build-up of lipids in other organs like the liver and pancreas.

The researchers say that further study will be needed to establish if lipid recycling is linked to the positive effects of weight loss on health, such as remission of type 2 diabetes.

They also found that the weight loss cleared out senescent cells, which are aging and damaged cells that accumulate in all tissues. The senescent cells cause harm because they no longer function properly and release signals that lead to tissue inflammation and scarring.

In contrast, the researchers found that weight loss did not improve the effects of obesity on certain aspects of the immune system. They found that inflammatory immune cells, which infiltrated the fat of people with obesity, did not fully recover even after weight loss. This type of inflammatory cell memory could be harmful in the long term if people regain weight.

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TOPICS: Health/Medicine
KEYWORDS: health; weight; weightloss

[ConservativeMind]

Fasting and a fasting mimicking diet are also shown to do this, in little time.

Autophagy, the recycling of cells and proteins, best happens during fasting and it preps stem cells for renewal once normal food is reintroduced.

It also keeps the inflammatory markers down over 20% for up to two months.

[ConservativeMind]

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[Bobbyvotes]

Must be true. I went down from 178 lbs down to 157 lbs. At age in mid-80’s. My blood sugar & blood pressure are now in normal range and have enough stamina to mow lawn with a push mower. But in my opinion the real key to my good health is daily mild aerobic exercise for 25 minutes.

[RoosterRedux]

But in my opinion the real key to my good health is daily mild aerobic exercise for 25 minutes.

That's good. I would recommend HIIT a couple of times a week and weight lifting (not too heavy, not too light).

Strength is more important than ever, as you get older.

I do both (vigorous cardio and lifting) and can attest to the benefits of such. If you have joint problems, work around them.

[sauropod]

Review

[TheThirdRuffian]

Most of my family lives past 100 or at least mid-90s, generally in excellent health.

The exceptions have been those who were fat. They die early.

[Bobbyvotes]

Weight lifting is not necessary in old age. I do treadmill with 1 lb weights on each wrist. There is no need to build extra muscles. That makes us more hungry. Walking on treadmill with wrist weights keeps my arms and shoulders strong.

[RoosterRedux]

Lifting weights (resistance training) becomes more important as we age—not less. Here's an old list I had on hand. Not sure where I got it.;-)

1. Prevents Muscle Loss (Sarcopenia): Starting around age 30, adults begin to lose muscle mass and strength—an effect that accelerates after 60. Resistance training is the only reliable way to slow or reverse this decline.

2. Preserves Bone Density: Weight-bearing and resistance exercises stimulate bone formation and slow bone loss, helping prevent osteoporosis and fractures.

3. Improves Balance and Prevents Falls: Stronger muscles support better posture (and less back strain), coordination, and balance—all critical for fall prevention, which is a major risk in older age.

4. Boosts Metabolism: Muscle tissue burns more calories at rest than fat. Maintaining muscle helps manage weight and blood sugar more effectively.

5. Supports Mental Health and Cognitive Function: Studies show resistance training reduces anxiety and depression, and may slow cognitive decline.

6. Improves Joint Function and Pain: Contrary to outdated myths, weight training improves joint health when done properly. It can reduce arthritis symptoms and increase mobility.

7. Promotes Independence: Maintaining muscle means maintaining the ability to get out of a chair, climb stairs, carry groceries, and live without assistance.

[woodbutcher1963]

I am 62. 5’ 9” male.
Mid December I started intermittent fasting because I reached the weight of 213.
Within a few weeks I dropped back under 200 for the first time in years.

The first week of January I went to my annual physical. I have genetically high chloresterol my entire adult life. Although my HDL has always been proportionally high. I tried five different statins. However, stopped all of them because of muscle weakness in my legs.
My total number dropped from 290 down to 205. Which it had not been that number since I was in my 20s.

Needless to say my GP Dr was amazed with the numbers/results. In addition. my blood sugar had also dropped somewhat.

I have continued to fast twice a week. Today and Thursdays.
Meaning I do not eat from Sunday night after dinner until Tuesday morning. Then repeat from Wednesday night after dinner until Friday morning.

My current weight this morning was 184.
I have a 20oz tumbler on my desk with water and an electrolyte packet in it with zero sugar.
FYI, my wife also does this. Which really helps with the moral support.

I have a buddy out in Idaho to thank for this. I am actually following his exact method. He has been doing it for about 3 years. He has lost over 50 pounds. His wife has lost 25.

[Bobbyvotes]

You may be talking about people below age 75. After 75 no one should strain any muscles by lifting weights, very easy to get sore muscles and they take a long time to heal after age 75.

I am 85, avoid weightlifting and have amazing muscles strength. I can mow grass with push mower, do all house repairs myself, so have adequate muscles. More muscles one has, more hunger pangs will one get. Last thing a super senior needs is excess weight. Where is the need for lot of muscles after age 75? Definitely not going to work for Fedex delivering packages. Every time I am at the gym, I see people exercising upper body with weights. Very bad idea for older folks. What seniors need is aerobic exercise to keep heart muscles strong and keep arteries free of fat deposits.

[Bobbyvotes]

I have done intermittent fasting to lower A1C and it worked.
Now I eat only 2 meals a day. A good breakfast at 9 Am and a early dinner at 4 PM. If get hungry in between, I snack ob fruit and yogurt.

You have done great job shedding excess pounds. Keep up the good work. It will give you extra years of life with better health. I am 85, and have zero medical issues and zero medical expenses. I may miss a meal but never miss daily treadmill brisk walk for 25 minutes.

[RoosterRedux]

That’s impressive—you’re clearly staying active and capable, which is the goal for all of us. But respectfully, the research doesn’t agree with the idea that people over 75 shouldn’t lift weights. In fact, resistance training is especially important after 75 to preserve muscle mass, bone density, balance, and metabolic health—all of which decline faster in those later years.

Of course, the approach has to be tailored: no one’s saying an 85-year-old should deadlift 300 lbs. But light resistance with proper form, even just bodyweight exercises or resistance bands, can make a big difference—and actually reduce soreness and injury risk over time by strengthening connective tissue and stabilizing joints.

Cardio is important too, but resistance training addresses things cardio can’t—like fall prevention, maintaining independence, and slowing sarcopenia. It’s not about bulking up, but about holding on to what matters most: function.

Glad you’re doing well—just adding a bit of perspective from current science.

[woodbutcher1963]

Good for you.
My father in law is 88. He hardly gets out of his chair anymore. It is actually sad. He used to be so much fun to be around.

You have to stay busy. Lately, I am working on scraping, sanding, repairing the second story windows on my 52 year old house. I think I was up and down that ladder and the house stairs at least 15 times yesterday and Saturday.

The more you sit around, the worse it becomes.

[Veto!]

I’m never hungry, don’t need to lose weight.
After I had a compound fracture of my right wrist, gave up weight lifting. I’m a small person and miss those weights.

In fact, my MD felt my upper arm muscles last year and told me: “You’re very strong. You’ll live to be 100”.

[Veto!]

Love that list. I live in a wonderful upstairs apartment with a beautiful view. 15 steps up. Many friendes won’t climb them but I’m up and down several times a day.

“How can you do all those steps?”

“I can do them because I do them.”

[RoosterRedux]

That’s a great way to stay fit.

I used to live in a fourth-floor apartment in an NYC townhouse, and when I first moved in, I figured the stairs would be no problem—I was a runner and cyclist, in good shape. But I was wrong. They were a real pain at first. But after a few weeks, everything changed—they stopped being a chore and actually became fun.

Amazing what consistency can do.

[Bobbyvotes]

You should do what you like.
All I do here is post my personal experience. I never imagined I would feel agile like a ballet dancer at age 85.
I am 5’-8” & 157 lbs.

[gitmo]

Mookbark.