Whether it's houses, TVs or cars - compared to decades ago, things have gone supersized.

And that includes serving sizes and waistlines. 

In 2024, 43 percent of Americans were considered obese, compared to just 13 percent in the 1960s. 

Experts have blamed an increased intake of ultra processed foods and meals with more calories and warned obesity can lead to a range of health problems, including heart disease, diabetes, high blood pressure, high cholesterol, liver disease, sleep apnea and certain cancers.

And now, California-based nutritionist Autumn Bates has revealed what she believes is driving the obesity epidemic, detailing four reasons as to why people were slimmer in decades gone by, despite exercising less or not having access to fitness monitors like Apple Watches and FitBits. 

She says she decided to investigate this phenomenon after watching a YouTube short recently that asked the question why were we so skinny in the 1960s?

The nutritionist said: '[This is a] fair question because in the 60s we had an obesity rate in America of about 13 percent. 

'To put that into perspective now currently as of 2025 we have an obesity rate that is closing in on 43 percent and this is all kind of wild because it's not like people were known in the 60s for their healthy food choices.

'So why in the world did we have such lower body fat percentages back in the 60s?'

The first driving factor behind the rise in obesity is the decline in home-cooked, fresh meals. These used to be the rule; not the exception.

They traditionally featured 'some type of really high quality protein, some fruit, some bread, some veggies and then probably milk.'

She explains this same nutritious formula applied to children's packed lunches for school, so kids were getting more of a balanced diet compared to today.

From her research looking at what people ate in the 1960s, Ms Bates says some of the popular items included roast chicken, meatloaf, beef stew, steak and potatoes.

There was little mention of fast food, which has seen a surge in serving sizes - with calorie counts reaching nearly 2,000 for a serving of popular burgers and fries.

From personal interactions with her family, she said in a YouTube video: 'My dad said that they would pretty much always have like pot roast and my mom has a very specific, not fond, memory of lima [or butter] beans.'