Interview with Professor Sarah Berry, Nutrition Scientist, Debunking Myths on Seed Oils, Metabolism, and Menopause Diet

Nutrition has become strangely noisy. One minute, we are told to avoid all carbs. The next minute, we are told to eat only meat. Then seed oils become the villain of the week, fasting gets framed as a miracle, and somewhere in the middle, most women are just trying to figure out what to eat to feel better, especially during perimenopause and menopause.

That’s why Professor Sarah Berry joins Dr. Thais Aliabadi and Mary Alice Haney for a refreshing conversation. She is a Professor at King’s College London, Chief Scientist at ZOE, and one of the leading researchers studying personalized nutrition. Her work sits at the intersection of metabolism, gut health, meal timing, blood sugar, fats, inflammation, and women’s health. Instead of relying on trends, she looks at what happens in large-scale human studies.

What came through most clearly is this: nutrition is more personalized than we used to think, but the basics still matter a lot. Most people do not need more food rules. They need better information, more consistency, and less confusion.

Table of Contents

• Personalized Nutrition, Food Myths, and What Really Matters
• Meal Timing, Eating Speed, and Why Lifestyle Shapes Metabolism
• The Pillars of Health Are Still Boring and Powerful
• What We Should Actually Be Eating
• Snacking Is Not the Enemy
• Gut Health, Prebiotics, and Probiotics
• Menopause, Blood Sugar, Brain Fog, and Food
• Fats, Cholesterol, Dairy, and Seed Oil Myths
• How to Find Nutrition Information You Can Actually Trust
• Food Should Support Health, but It Should Also Still Be Enjoyed
• FAQ

Personalized Nutrition, Food Myths, and What Really Matters

How did you get into personalized nutrition, and why has it become such an important field?

Professor Berry started in physiology more than 25 years ago, before nutrition had become the center of every social media debate. During her PhD, she ran randomized controlled trials in healthy adults, testing different types of fats and measuring cardiometabolic outcomes. That early work shaped her approach. She fell in love not just with nutrition, but with clinical trials and the discipline of testing ideas properly.

About seven years before this conversation, she joined a small team at ZOE that was exploring what was then a novel research area called personalized nutrition. The idea was simple but powerful: people do not all respond to food in the same way.

That led to the PREDICT research program, which has now studied more than 250,000 people. The scale matters because it allows researchers to look not just at food itself, but at all the variables wrapped around food. Age, sex, menopause status, body composition, genetics, gut microbiome, stress, sleep, meal timing, fasting window, and eating speed all influence metabolic response.

That is a major shift from old-school nutrition advice. Instead of asking only, “Is this food good or bad?” the better question becomes, “How does this person respond to this food in this context?”

What makes this research different from traditional nutrition studies?

A lot of nutrition advice has historically come from broad population-level recommendations. Useful, yes, but often too blunt to explain why one person feels great on a certain eating pattern while another struggles with energy crashes, hunger, or blood sugar spikes.

Professor Berry’s team collects data in a much more detailed way. Participants use remote testing tools, including:

• Continuous glucose monitors to track blood sugar responses

• Blood sampling devices to measure metabolic markers

• Stool tests to assess the gut microbiome

• App-based logs for hunger, mood, energy, and food intake

• Questionnaires about family history, lifestyle, and health status

They also receive standardized “challenge meals” that are intentionally high in fat and carbohydrate. These meals are not meant to be healthy. They are meant to stress the system so researchers can see how flexible a person’s metabolism really is.

After those meals, the team measures glucose and post-meal blood fats, especially triglycerides. These post-meal responses matter because repeated excessive spikes in glucose, triglycerides, and inflammation are linked to long-term metabolic disease risk.

Importantly, a healthy body does have temporary rises in glucose and fats after meals. The problem is not a normal rise. The problem is when those responses are excessive, repeated, and happening day after day.

So are food labels telling the full story?

Not really. Labels can tell us how many calories, grams of fat, or grams of sugar are in something. They do not tell us how that food will interact with a specific person’s biology, schedule, stress level, sleep, or gut microbiome.

That is one of the most important takeaways from Professor Berry’s work. It is not just what we eat. It is also how we eat, when we eat, and what is going on in our bodies and lives when we eat it.

Meal Timing, Eating Speed, and Why Lifestyle Shapes Metabolism

What did you find about eating speed?

This was one of the most practical and immediately useful parts of the conversation.

People tend to eat too fast. And according to Professor Berry, eating fast is associated with poorer metabolic health, larger blood sugar spikes, and a higher likelihood of being overweight compared with slower eaters.

The mechanism is intuitive. Fullness signals take time. If we eat too quickly, the food does not get far enough into the digestive system for the lower gut signals to properly communicate satiety. We overshoot before the body has a chance to say, “That is enough.”

Even more striking, slowing eating speed by just 20% can reduce calorie intake by about 15%.

That means one of the simplest nutrition strategies is not a supplement, detox, or restrictive meal plan. It is eating a little more slowly.

For many of us, that may mean:

• Putting the fork down between bites

• Not eating while scrolling or rushing

• Taking a breath before going for seconds

• Actually chewing properly

How important is meal timing?

Very important. Professor Berry’s research suggests that eating late into the evening is associated with poorer metabolic health. In their data, people who snacked after 9 p.m. had worse inflammation, less favorable cholesterol, higher waist circumference, and higher BMI.

The practical takeaway was straightforward: if possible, try to stop eating by around 8 p.m.

That does not mean one late dinner ruins your health. It means the pattern matters. Chronically eating late seems to work against the body’s natural rhythms.

Our cells operate on circadian clocks. Eating very late can push food intake out of sync with those internal clocks. Overnight, the body appears to benefit from a period of rest from digestion and nutrient processing.

What about fasting or time-restricted eating?

ZOE conducted a large intermittent fasting study involving 150,000 people. The approach was not extreme. Participants were simply asked to reduce their eating window to 10 hours, leaving 14 hours overnight without food.

That is far more realistic than rigid fasting schedules that many people cannot maintain. In the US and UK, many people naturally eat across a 12.5- to 13-hour span, so shrinking that window to 10 hours is often only a modest adjustment.

The results were meaningful. Participants reported improvements in:

• Mood

• Energy

• Body weight

People who ate earlier in the day seemed to do even better. A sample schedule mentioned in the conversation was breakfast at 8:30 a.m. and dinner finished by 6:30 p.m. That pattern fits a 10-hour eating window and leaves the body a longer overnight fasting period.

One especially practical behavioral tip came up in the conversation: brushing teeth after dinner to signal that eating is done for the night. Sometimes metabolism and habit work best together.

Are the benefits of time-restricted eating just from eating fewer calories?

Partly, yes. Professor Berry explained that a natural consequence of a shorter eating window is often lower calorie intake. The more restricted the feeding window, the fewer calories people tend to consume.

But there may be more going on than calorie reduction alone. Circadian biology likely plays a role. Eating in alignment with our body clock appears to support metabolism better than eating late at night. In other words, timing may matter both because it changes intake and because it changes physiology.

The Pillars of Health Are Still Boring and Powerful

If nutrition is personalized, does that mean everyone needs a completely different diet?

Not exactly. This is where the conversation became wonderfully sane.

Professor Berry made the point that while there is room for optimization, most people are not even doing the basics. So before obsessing over micronutrient hacks or niche food rules, it makes more sense to focus on the foundation.

Her core pillars of health are:

• Diet

• Physical activity

• Sleep

• Stress management

These interact constantly. Poor sleep affects food choices and blood sugar responses. Exercise changes how we metabolize food. Stress can drive cravings and disrupt routines. Focusing on one pillar while ignoring the others misses the bigger picture.

This is particularly relevant for women in midlife, when sleep disruption, changing hormones, increased insulin resistance, and shifts in body composition all start to collide. If that sounds familiar, there is helpful context in this resource on menopause and weight gain, especially around insulin resistance and abdominal fat changes.

How does sleep influence what and how we eat?

Poor sleep does more than leave us tired. Professor Berry noted that when we do not sleep well, the reward centers in the brain become more active, making us crave quick-fix foods like sugary pastries or refined carbs.

Her team has also found that after a poor night’s sleep, post-meal glucose responses are worse than after a good night’s sleep. So sleep does not just affect what we choose. It also affects how our body processes what we choose.

For women in perimenopause and menopause, sleep disruption is often one of the most persistent symptoms. If fatigue is part of the picture, this guide on menopausal fatigue offers a useful look at why it happens and what may help.

What We Should Actually Be Eating

With so much misinformation online, what are the most basic principles of healthy eating?

Professor Berry’s answer was simple, clear, and refreshingly unglamorous.

She said the basics are “boring and simple,” and that is a good thing.

Her practical plate framework looked like this:

• Half the plate should be plant-based, minimally processed foods such as vegetables, beans, and similar whole foods.

• One quarter can be whole grains such as brown rice or quinoa.

• One quarter can be a protein source, whether animal-based or plant-based, depending on preference.

That is not a trendy formula. It is a durable one.

She also emphasized that nearly everyone would benefit from:

• More fiber

• More fruits and vegetables

• More pulses and legumes

• Moderating red meat

• Reducing ultra-processed foods

• Reducing free sugars

• Moderating salt intake

Why is food diversity so important?

One of the more interesting points from the discussion was that healthy eating is not just about checking off a few “good foods.” It is also about variety.

Different plants provide different fibers and polyphenols. Those compounds help nourish different species in the gut microbiome. That diversity in the gut appears to matter for overall health.

The practical rule of thumb Professor Berry gave was to aim for about 30 different plant foods per week.

That count includes more than produce. It can include:

• Vegetables

• Fruits

• Beans and lentils

• Nuts and seeds

• Herbs and spices

• Whole grains

“Eat the rainbow” may sound cliché, but there is real science behind it.

What about ultra-processed foods?

This was one of the strongest, clearest messages in the entire conversation.

Rather than demonizing one nutrient, Professor Berry encouraged a food-first approach. Try to eat foods that still resemble their original state.

Ultra-processed foods often have altered food structure, low fiber, added sugars, excess salt, and multiple additives. That combination appears to be much more problematic than any single isolated ingredient.

She also acknowledged the reality that this is harder than it sounds. Whole-food meals are often more expensive, and many households are juggling work, kids, fatigue, and limited time. This is important because nutrition advice that ignores real life is not useful.

Still, even small changes matter. Learning a few simple from-scratch meals, keeping ingredients on hand, and improving snack quality can go a long way.

Snacking Is Not the Enemy

Is snacking good or bad?

According to Professor Berry, snacking itself is not inherently bad.

What matters is:

• What you snack on

• When you snack

Her research found that regular snacking on healthy foods was not associated with harm. What was problematic was late-night snacking after 8 or 9 p.m.

This is good news because snacking is one area of eating that many people can control more easily than family dinners or social meals. You may not choose every dinner menu in your household, but you often can choose your own snacks.

What is a better snack choice?

One study she discussed compared almonds with more typical snack foods. The almond group had significantly better blood vessel function. The estimated difference translates to about a 30% lower cardiovascular disease risk compared with those eating typical snacks.

That kind of finding is powerful because it shows that one small swap can matter. Better nutrition does not always require overhauling your whole life. Sometimes it starts with replacing one habitual snack.

Gut Health, Prebiotics, and Probiotics

Is gut health the key to disease prevention?

Professor Berry was careful here, and that caution is worth appreciating.

She did not oversell the microbiome as the answer to everything. Instead, she said the field is incredibly exciting, clearly important, and still developing. The data from ZOE repeatedly show strong links between gut microbiome composition and many health outcomes. But there is still a lot we do not know.

That kind of answer may be less flashy than social media certainty, but it is much more trustworthy.

Should people take prebiotics or probiotics?

Her answer leaned more confidently toward prebiotics.

Prebiotics are the compounds that feed beneficial gut microbes. These include fibers and polyphenols found in plant foods. There is good evidence that they support the microbiome and can positively influence health.

Probiotics also show promise, and she said there is generally no harm in taking them. But the science is still catching up in terms of which strains do what, for whom, and in what contexts. So while probiotics may help, the evidence is not yet precise enough to make highly specific strain-by-strain recommendations in most situations.

The practical message was clear: start by feeding the gut well. That means more fiber, more plants, more diversity, and more fermented foods.

Menopause, Blood Sugar, Brain Fog, and Food

Does metabolism really change in menopause?

Yes, and Professor Berry’s research adds important detail to what many women already feel in their own bodies.

Using data from the PREDICT program, her team looked at health markers in premenopausal and postmenopausal women. Postmenopausal women had:

• Higher cholesterol

• Higher inflammation

• Worse blood pressure

• Higher post-meal blood sugar responses

And importantly, the team was able to do age matching in the analysis. That matters because menopause and aging happen at the same time, which can make it hard to tease apart what is due to hormone changes versus just getting older. Their analysis suggested that menopause status itself, independent of age, affects how food is processed.

This aligns with what Dr. Aliabadi pointed out in the conversation as well: as women move through menopause, insulin resistance often increases, making weight and metabolic control more challenging. For anyone managing blood sugar changes during this stage, this article on diabetes and menopause gives additional practical context.

What did the menopause symptom research show?

This part of the conversation was genuinely eye-opening.

In a study of 70,000 women, Professor Berry’s team looked at menopause symptoms and their relationship to diet. The surprising finding was not just how common symptoms were, but which symptoms were most common.

We often think of menopause mainly in terms of hot flashes and night sweats. But in this research, those were among the least common symptoms.

Instead, the most common symptoms included:

• Brain fog

• Anxiety

• Low mood

• Depression

• Memory loss

• Poor sleep

The numbers were striking:

• 99% of perimenopausal women reported at least one symptom

• 66% reported 12 or more symptoms

• 85% reported brain fog, anxiety, low mood, depression, or memory issues

• 85% reported poor sleep

That matters because it broadens the conversation around menopause. Women who are struggling with concentration or memory changes are not imagining things, and they are not alone. For a deeper look at that specific symptom cluster, this page on menopausal memory loss may be helpful.

Can diet actually help with menopause symptoms?

According to Professor Berry’s work, yes.

Her team followed participants in ZOE’s personalized nutrition program over 12 weeks. By the end of the program, women had about a 35% reduction in menopause symptoms compared with the beginning.

The changes were not built around an extreme plan. The dietary shifts focused on increasing:

• Unprocessed fruits and vegetables

• Fiber

• Fermented foods

• Gut-friendly whole foods

Professor Berry was careful to note that this was not a randomized controlled trial and did not include a control arm, so it should not be overinterpreted. But a 35% symptom reduction is still impressive, especially because the effect appeared whether or not women were also taking hormone replacement therapy.

That reinforces a valuable point: nutrition is not necessarily an alternative to medical treatment, and it does not need to compete with HRT. It can be a meaningful support alongside medical care.

Fats, Cholesterol, Dairy, and Seed Oil Myths

What is the biggest misconception about fat and cholesterol?

Professor Berry was emphatic that the conversation around fats is too simplistic.

“Fat raises cholesterol” is not an accurate statement.

Her point was more nuanced:

• Some saturated fats raise cholesterol.

• Not all fats behave the same way.

• Not all dairy affects cholesterol in the same way.

For example, she noted that fermented dairy such as cheese and yogurt does not seem to raise cholesterol the way butter does. That is a good reminder that food structure matters. The same broad category of food can behave differently depending on processing and composition.

Are seed oils really harmful?

This was one of the central myth-busting moments of the conversation.

Professor Berry said plainly that she is positive on seed oils and believes they are healthy based on human randomized controlled trial evidence. The common seed oils she referenced included:

• Canola oil

• Soybean oil

• Sunflower oil

According to the research she cited, these oils do not show harmful effects in human trials. If anything, they appear beneficial, particularly because they can lower LDL cholesterol and ApoB levels.

They contain omega-6 fats, which have been unfairly blamed in some online narratives. She pointed out that the arguments against seed oils often rely on weak forms of evidence, such as animal studies, cell culture work, or correlation-based claims rather than strong human trials.

Why do so many people think seed oils are the problem?

Because the story sounds tidy.

Seed oil intake rose over the same decades that obesity, type 2 diabetes, and cardiovascular disease also increased. But correlation is not causation. Many things changed over that same period, including ultra-processed food consumption, total calorie intake, physical activity patterns, sleep, stress, and food environments.

Professor Berry made a key distinction: much of the seed oil people consume is inside ultra-processed foods. That is a problem. But the problem is likely the ultra-processed food overall, not the seed oil itself in isolation.

That is an important difference. It means we should be wary of highly processed packaged foods, but not automatically fear every bottle of canola or sunflower oil in a home kitchen.

So what should we do instead of demonizing one ingredient?

Think in terms of whole dietary patterns, not villains.

Professor Berry urged a food-first approach. Ask:

• Is this food minimally processed?

• Does it contain fiber?

• Does it resemble real food?

• Is it replacing something worse or being added to an otherwise poor-quality diet?

Nutrition misinformation often becomes cult-like because it offers certainty. Real science usually sounds more nuanced. That nuance is a feature, not a flaw.

How to Find Nutrition Information You Can Actually Trust

Where should women go for evidence-based nutrition advice?

Professor Berry said she always goes back to the original research, but she also acknowledged that scientific papers are not easy reading for most people.

Her recommendations for reliable information included:

• The ZOE Science & Nutrition podcast

• University-based resources such as Harvard

• Organizations grounded in nutrition science, such as the British Nutrition Foundation

• Research-active scientists who communicate evidence responsibly

That last point matters. There is a big difference between someone with a confident opinion and someone who has actually run human trials.

The bigger warning from this conversation was about where many people now get their nutrition information: TikTok and Instagram. Those platforms can be useful, but they can also flatten complex science into catchy, misleading slogans. And once food advice becomes identity-based, it gets very hard to challenge.

Food Should Support Health, but It Should Also Still Be Enjoyed

What is the most important takeaway from all of this?

If we had to distill the conversation into a few grounded principles, they would be these:

• Nutrition is personalized, but the basics are still universal.

• Eat more fiber and more minimally processed plant foods.

• Aim for diversity, not perfection.

• Slow down when you eat.

• Try to avoid late-night eating.

• A 10-hour eating window may be a realistic, beneficial target for many people.

• Snacking is not bad if the snack and timing are sensible.

• Menopause changes metabolism, but nutrition can meaningfully help.

• Seed oils are not the nutritional villain social media makes them out to be

• Do not let food fear replace food enjoyment.

That final point may be the one we most need to hear. Professor Berry ended with a reminder that food is not just fuel. It is pleasure, culture, emotion, connection, and joy. In the rush to optimize everything, we can lose sight of that.

There is no magic pill. There is no perfect diet. There is no single ingredient to blame or one secret rule that solves everything. But there is a lot of power in returning to basics and being consistent with them.

FAQs

What is personalized nutrition?

Personalized nutrition is the idea that different people respond differently to the same foods. Those differences can be influenced by gut microbiome composition, genetics, sleep, stress, meal timing, eating speed, age, body composition, and menopause status.

Does eating late at night affect metabolism?

Yes. Professor Sarah Berry discussed research showing that late-night eating and snacking after 8 or 9 p.m. are associated with poorer metabolic health, including worse inflammation, cholesterol, BMI, and waist circumference.

Is a 10-hour eating window beneficial?

For many people, yes. In a large study, reducing the eating window to 10 hours was associated with improvements in mood, energy, and body weight. Earlier eating windows appeared to offer even more benefit.

Does eating more slowly really help?

Yes. Eating too quickly is associated with worse metabolic health and bigger blood sugar spikes. Slowing eating speed by about 20% may reduce calorie intake by around 15% because it gives fullness signals more time to work.

Are seed oils bad for you?

Based on the evidence Professor Berry discussed, common seed oils such as canola, soybean, and sunflower oil are not harmful in human randomized controlled trials and may even improve cholesterol markers. The bigger issue is often the ultra-processed foods that contain them, not the oils alone.

What are the best basic nutrition habits for menopause?

The most helpful pattern discussed included more minimally processed fruits and vegetables, more fiber, more fermented foods, greater plant diversity, less ultra-processed food, and better meal timing. These changes were associated with meaningful improvements in menopause symptoms.

Should everyone take probiotics?

Professor Berry said probiotics appear promising and are generally safe, but the science is still evolving on which strains are best for specific outcomes. She was more confident about prebiotics, meaning the fibers and polyphenols in plant foods that feed healthy gut microbes.

How many plant foods should we aim for each week?

A practical goal mentioned in the conversation was about 30 different plant-based foods per week. That includes fruits, vegetables, legumes, nuts, seeds, herbs, spices, and whole grains.

This article was created from the video Debunking Myths on Seed Oils, Metabolism, & Menopause Diet with Professor Sarah Berry | SHE MD for Dr. Thais Aliabadi’s website.