Why Grandma’s Recipes Didn’t Make Us Fat: The Hidden Role of Processed Foods, Chemicals, and Modern Life

It hasn't made sense to me that my grandmother's recipes are filled with sugar and butter, yet the Boomer generation didn’t have obesity and metabolic syndrome in their 20s.

As I bake through my grandmother’s cookbooks, handwritten in the 1930s and 1940s, most recipes call for sugar and butter. Meat and potatoes were common. But the boomer generation didn't have metabolic syndrome in their 20s or cancer in their 30s and 40s for the most part.

As diets removed butter, sugar, meat, and starches, obesity ballooned. Between 2010 and 2020, obesity rose the fastest in young adults. From their 20s to 40s, obesity rose more in this age group than for those older than 60. Those are the boomers who grew up drinking whole milk, eating bread and butter and some desserts made with sugar.

These younger generations (ours included, millennials!) are obese earlier and for longer. In 2019, over 38 million children under the age of 5 were overweight or obese across the world.

We’ve probably all heard these horrific statistics:

• The rate of obesity in U.S. adults doubled between 1990 and 2021

• 75% of U.S. adults are overweight or obese

  
  

Many women I see are experiencing the change for themselves.

How are overweight and obesity defined?

Overweight is defined as BMI (body mass index) of 25-29.9

Obesity is defined as BMI 30+. This is then broken down into classes based on severity.

• Class 1: BMI 30-34.9

• Class 2: BMI 35-39.9

• Class 3: BMI 40

  
  

We’ve blamed a lot of factors:

• Fat

• Sugar

• Sedentary lives

• High fructose corn syrup

• Preservatives

  
  

These each has its own role, but none is a smoking gun.

Why not just diet?

I’ve heard many women say that they've cut calories, cut carbs, started exercising and nothing changed.

While these can all be beneficial to some extent, it doesn't seem to completely explain the problem.

Especially as we hit menopause, when metabolically we become more like men (belly fat, anyone?), it's an uphill battle.

I want to encourage routine exercise with real challenge and a diet full of whole foods, but this doesn't seem to be the whole picture.

So what else is contributing?

#1 What’s in the calories?

The same number of calories from whole foods versus processed or ultra-processed foods will be handled differently by the body.

I grew up hearing the term "in moderation”. Processed or highly processed in moderation may not completely derail your metabolism. The problem is moderation doesn't exist.

Over 60% of the American diet is now ultra processed. It's even more in children, sadly, at around 70%.

Ultra processed can be something as seemingly simple as store-bought bread or flavored yogurt. And of course it includes soda, chips, and candy.

There is evidence that ultra-processed foods increase the risk of:

• obesity by 50%

• cardiovascular death by 66%

• colorectal cancer by 29%

  
  

#2 What do the calories do?

It turns out that ultra processed foods lead to more eating, even if someone is full.

There’s a well-known study in humans where participants spent two weeks with pre-portioned meals. They were equal in calories, sugar, and macronutrients between study groups. The difference was the amount of processing, thereby the nutrient content of the foods.

The fewer the nutrients, the more calories consumed.

In a newer study, young adults were studied in a similar way but participants didn't have free access to food so the calories couldn't just be increased. The youngest group in particular, ages 18 to 21, ate more after an ultra-processed diet and snacked even when they didn't feel hungry.

The ultra-processed foods and its components disrupt gut health which contributes to inflammation.

#2 What’s in the internal environment?

Internally, it's not just our food we're taking in. We are ingesting or exposed to chemicals in excess and unprecedented amounts.

You may not have known that because products aren't advertised that way. The marketing teams aren't selling “endocrine disruptors that alter bodily function”, they're selling fragrance you enjoy and products you think you need. They’re supposed to make you feel good.

But how good do we really feel?

I see a lot of women. Most don't feel well at all.

It turns out these products are filled with endocrine disrupting chemicals (EDCs) which means they alter processes in our bodies. Our carefully curated cellular processes are derailed by these chemicals. Cellular processes including fat storage.

Some of these EDCs including:

• Bisphenol A: used in plastics, personal care and household items

• Bisphenol S: used as a replacement for Bisphenol A

• DDT, DDE: used in pesticides

• Phthalates: used in cosmetics, plastics

• Parabens: used as cosmetic preservatives/anti-bacterial

  
  

These EDCs and others have been shown to increase obesity, inflammation, leptin, body weight, insulin resistance, and cholesterol.

Sadly, there is no comprehensive library of all these chemicals.

#3 What's in the external environment?

Our external environmental exposures play a large role here.

Externally, we are exposed to screens almost constantly. Adults use screens on average about 7 hours per day. Teenagers are at least 4 hours per day. Children are getting multiple hours per day of screen time.

This doesn’t foster an environment of activity, play, or exercise whether mental or physical.

Beyond lack of activity, our modern way of life that demands function around the clock actually disrupts our genes and metabolism. We have genes called clock genes that regulate our bodily functions based on the time of day. We have an internal clock and we receive external cues from light and dark.

The modern way of life is to see a screen, artificial light, and eat around the clock. This disruption is called chronodisruption. Mouse models with disruption of their clock genes are prone to obesity and metabolic syndrome.

I personally know this very well from an on-call schedule. I know that if I'm up all night, I’ll eat without being hungry and usually not healthy foods. I’m completely out of my rhythm and it feels like I'm not even making the decision.

There's a hormonal reason for that. Just one disrupted night of sleep leads to an increase in the hormone ghrelin, the hormone that signals hunger.

Most doctors I know have some sort of call snack, their go-to food when they're on call or have just finished call. It's usually junk food.

What can you do?

Reduce or strive to eliminate ultra-processed foods, limit processed foods and consume mostly whole foods. Try to cook at home using household ingredients.

Reduce your toxic load. Look at your household one area at a time: kitchen, bathroom, self-care drawer, cleaning supply closet. Swap out products with fragrance, dyes, and the above listed compounds.

Reduce your screen time, especially at night.

Reduce your other inputs (besides light) at night: exercise, food, drink.

Sleep, as much as in keeping with natural light and dark as possible. Avoid screen time for hours before bed. I actually love these new circadian light bulbs I'm using for a very warm wind-down light. (Use Code NAZZARO for 10% off)

It turns out the soups, meatloaf, pot pies, bread and cakes made at home by my grandmother just weren't doing the same damage as the packaged versions of today. Cook at home with your family and multiple generations will benefit.

Resources:

Some of the information contained in this article is the result of my training, medical knowledge, and personal experience without a specific source to be cited.

The author can earn commissions through affiliate links.

Disclaimer: This is not medical advice. This is for educational purposes only. Discuss with your doctor.

https://healthactioncouncil.org/media/i5qj3qah/2025-hac-white-paper.pdf

https://pmc.ncbi.nlm.nih.gov/articles/PMC8597017/

https://www.cdc.gov/nchs/products/databriefs/db513.htm#:~:text=(NHIS–Teen)-,About one-half of teenagers had 4 hours or more, Figure 1, Table 1).

https://news.vt.edu/articles/2025/11/research_fralinbiomed_difedavyobesity.html

https://pmc.ncbi.nlm.nih.gov/articles/PMC8655100/

https://www.mdpi.com/2673-4168/5/2/48

https://pubmed.ncbi.nlm.nih.gov/18564298/

https://med.stanford.edu/news/insights/2025/07/ultra-processed-food--five-things-to-know.html#:~:text=In one randomized, controlled study, increased stomach discomfort after

eating.