Carbs, Weight & the Midlife Brain—Plus a Book Worth Reading

June Midlife Roundup [2025]

Photo by Ann on Unsplash

I recently came back from a relaxing vacation in Mexico. After this jam-packed year, it was just what I needed.

We hit the gym most mornings, which made lying around on the beach all the better.

With my oldest now a high school graduate, it’s becoming clear that I need to change some things. I’ll end this post with a book that came at the perfect time for me.

But first I’m discussing some widely publicized [midlife] studies—and digging into what they mean for women.

First up, carbs and midlife women.

Quality Carbs and Healthy Aging

There were many headlines about carbs at midlife, including a piece in Good Morning America: Women who eat the ‘right’ carbs in midlife are more likely to age in good health.

Researchers analyzed data from the Nurses’ Health Study, which surveyed women every four years between 1984 and 2016. They looked at how midlife diets (average age 48) impacted the long-term health of over 47,000 women, who were between the ages of 70 and 93 in 2016.

Here’s what they found:

• Only 7.8% met the criteria for healthy aging.

• About 32% (15,056 women) remained free of 11 major chronic diseases.

• Nearly half (48.8% or 23,196 women) reported no memory problems.

• Around 15% (7,300 women) had no physical limitations.

• And 38.3% (18,204 women) maintained good mental health.

Every 10% increase in carbohydrate intake led to a 17% increase in markers of healthy aging. For quality carbs like fruits, vegetables, legumes, and whole grains, this jumped to 31%. Refined carbs reduced the likelihood of healthy aging, while fiber intake promoted it.

“We’ve all heard that different carbohydrates can affect health differently, whether for weight, energy, or blood sugar levels. But rather than just look at the immediate effects of these macronutrients, we wanted to understand what they might mean for good health 30 years later,” said Andres Ardisson Korat, lead author said in a news release.

“Our findings suggest that carbohydrate quality may be an important factor in healthy aging.”

These findings line up with other evidence on carbs. Quality carbs and fiber benefit women by feeding a healthy gut, providing important micronutrients, and filling us up.

READ: Optimally Fueling Your Gut Microbiome

It’s important to note that these associations were independent of the women’s BMI. That means women gained benefits regardless of their weight.

Unfortunately, the next study ignores lifestyle, focusing solely on weight.

Does midlife weight loss help you live longer?

The headlines read:

Midlife Weight Loss Linked to Longer Healthier Lives

Study: Weight Loss in Midlife age Might add Years to Your Life

The study in JAMA Network included three different cohorts from Finland, age 30-50 at the beginning and followed for 12 to 35 years. Researchers split people into groups to study their health and how long they lived.

• Persistent healthy weight (BMI<25)

• Midlife weight loss (lost and maintained 6.5% weight, from BMI >25 to <25)

• Weight gain

• Persistent overweight

By the end of the follow-up period:

• 29.3% of women in the persistent healthy weight developed a health condition.

• 27.1% of those who lost weight in midlife did as well.

• In contrast, 36.1% of those who gained weight and 45.2% of those in persistent overweight developed a health condition.

These last two groups had a higher risk of chronic disease (morbidity).

After 35 years, the average number of survival years was:

• 33.9 for those with a persistent healthy weight

• 33.0 for those who lost weight

• 32.3 for those who gained weight

• 31.0 for those who remained overweight

I searched for specifics about these groups in terms of lifestyle factors and all I could find was that in all the groups except the weight loss group, physical activity decreased.

“I hope the findings will inspire people to see that lifestyle changes can lead to major health improvements and a longer life. This is particularly important today as more people are overweight than when the collection of our research data began 35 years ago,” Professor Timo Strandberg notes in a press release.

What? How can a study that fails to investigate lifestyle factors make such a conclusion? The previous study looked at carb quality and not just “total carbs.”

Most likely, the weight loss group took part in healthy habits like exercise, sleep and quality diet. And those that gained weight were likely less active and perhaps stressed. Is it the weight or the habits?

We know that weight is less telling with aging and what matters most is metabolic health. Not total body fat, but where it’s stored and how healthy it is. Yes, more muscle mass but also high-quality muscle.

Come on guys, we can do better than this! Studies that generalize are totally useless to midlife women. “Lose weight to live longer” is a step backwards, in my opinion.

Midlife brain headlines

Two studies about the midlife brain came out around the same time. One focused on the link between depression and dementia risk.

The first was based on an umbrella review (and meta-analysis)— a study that looks at multiple reviews — and found that depression in midlife increases the risk of developing dementia by 56%. For those with late-life depression, the risk jumps to 95%.

Then the press went crazy linking cortisol to Alzheimer’s risk. The study behind the headlines examined 305 cognitively healthy midlife adults and followed them for 15 years. Turns out, higher cortisol levels around midlife were tied to more amyloid in the brain later in life.

But this only occurred in postmenopausal women.

What’s interesting is that depressed people tend to have higher cortisol levels. In a review of cortisol and mental disorders, this following conclusion was made:

The studies conducted so far indicate that an increase in cortisol secretion is observed during many mental disorders, such as depression, BD, or schizophrenia. However, the applied therapy normalizes the activity of the HPA axis. In most cases, a decrease in cortisol levels also correlates with improvement in the patient’s condition. Moreover, studies indicate that cortisol determination may be helpful in predicting the effectiveness of a therapy.

When I see news reports on the latest study, I try to understand how it fits in the big picture. As I’ve talked about many times before, a woman’s nervous system changes at midlife at a faster rate than men’s do, then menopause comes along and speeds everything up.

Our emotional and mental health is so important at this stage, so women should seek help.

Yet it’s not always about hormones or even nervous system work. This book I’m sharing with you addresses another factor worth considering.

The Big Leap

In 2016, I changed my website and wrote about how I’m always hiding. This is how I put it:

I realize I tend to hide behind my writing, and to a certain extent, I hide in life, too. Although I’ve done a lot of cool stuff ― and make a point not to let fear hold me back ― I feel a little too comfortable when the light isn’t shined directly on me. Some light is fine, but too much makes me squeamish. This can lead to a tendency to play it safe, especially professionally.

That announcement was meant to get me out of hiding, but it didn’t. I know the why behind it based on my history. I’ve done therapy and even better, no-cost therapy sessions with friends. Yet safe and familiar ways of being die hard. They are seared into our nervous system.

One of my biggest excuses has been my children and my empathetic way of parenting. With my oldest graduating, I’ve been thinking about this more. And then I heard of this book [the Big Leap] on Instagram, I instantly downloaded it. And it spoke to me.

The primary premise is that, to a certain extent, all humans have an Upper Limit Problem. That is the unconscious ceiling for the level of happiness, success, and positive feelings we have. When we hit the ceiling, we pull ourselves back.

The author Gay Hendricks puts it this way:

Each of us has an inner thermostat setting that determines how much love, success, and creativity we allow ourselves to enjoy. When we exceed our inner thermostat setting, we will often do something to sabotage ourselves, causing us to drop back into the old, familiar zone where we feel secure.

The book details how to break that habit and allow yourself to raise that ceiling and live in what Hendricks calls the Zone of Genius. While this is just a theory, it’s an empowering way to look at how you live your life.

While hormonal and physical changes at midlife can increase the risk of anxiety and depression, sometimes the issue is that we’re not living in alignment with our potential. We can often be our own worst enemy—and this book shows you how to get out of your own way.

Midlife Morning Show

A quick update. Ann Marie and I still plan on holding Substack lives, but we want to schedule them with a topic. Look for those updates soon.

Let me know how you feel about the latest news and this book. Have you read it?