Improving your diet: How small changes make big differences

With ZOE, no food is off the table. Food is there to be enjoyed, and if you feel like you’re restricting yourself on your quest to eat healthily, you’re almost guaranteed to give up, be unhappy, or both.

Some internet “experts” promote sweeping, large-scale changes. These huge and inconvenient shifts can seem so extreme that they must work. In some strange way, the extremeness seems alluring.

“Give up all meat,” “Only eat meat,” “Avoid all additives,” “Never eat sugar.” 

None of these are possible, none of these are necessary for good health, and all will cause you stress and ultimately lead to a sense of failure.

That’s why we advocate for small changes that you can stick to. These will eventually become habits that are automatic — you won’t have to think about them anymore, and they won’t seem like a chore.

Before we go any further, we need to briefly explain what “dose-response relationship” means, because it comes up a bunch. 

What’s a dose-response relationship?

If you drink one glass of wine, you might get a bit of a fuzzy head. If you have two glasses, you’ll feel more fuzzy and perhaps quite merry. After four, you may be very fuzzy and merry, and after six, your brain and legs might fail you.

This is a dose-response relationship: The more you have of a particular thing, the more effect it has. 

Not everything works in this way, but when scientists identify a dose-response relationship between a food and a health outcome, it’s a strong clue that the measured benefits are related to the food. 

We should also mention that dose-response relationships generally break down at some point. 

For instance, 5 g, 10 g, and 15 g of fruit per day might provide increasing health benefits. But 1,500 g of fruit each day will probably make you sick.

Below, we look at studies that investigate dose-response relationships between foods and health. They show that even a fairly small change can have measurable benefits.

Again, keep in mind that these studies are looking at the effects of foods eaten in “normal” amounts — this is not an excuse to eat 50 avocados per day.

Instead, we want to show that, however small the change, it all counts in the long run. Increasing your “dose” of healthy foods improves your health “response” — even if the changes you make seem small.

Powerful plants

Anyone who’s followed ZOE for any length of time will know we’re passionate about plants. Research shows that a diverse, plant-based diet is associated with better long-term health.

We recommend aiming for 30 different plants per week to ensure you consume a wide variety of healthy plant compounds, vitamins, minerals, and fiber. 

Some studies have shown that upping your intake can improve health in a dose-response manner:

Plants, heart health, and cancer

A review and meta-analysis explored whether eating more fruit and veg had a dose-response relationship with cardiovascular disease, cancer, and mortality risk.

The scientists found that every 200 grams (7 oz) of fruit and veg consumed per day — roughly the weight of two apples — was associated with an:

• 8% reduced risk of coronary heart disease

• 16% reduced risk of stroke 

• 8% reduced risk of cardiovascular disease

• 3% reduced risk of cancer

• 10% reduced mortality risk

Let’s put these percentages into perspective. We'll use “16% reduced risk of stroke” as an example:

Plant intake and disease 

Another meta-analysis looked at fruit and veg intake and the risk of various diseases. 

They found that each 3.5 oz (100 g) per day increase in fruit was associated with a: 

• 44% lower risk of esophageal cancer

• 28% lower risk of mouth, pharynx, and larynx cancer 

Similarly, each 3.5 oz (100 g) per day increase in vegetable intake was associated with a:

• 12% lower risk of one type of kidney cancer

• 11% lower risk of non-Hodgkin lymphoma

A couple of sticks of celery or a large carrot weigh around 3.5 oz (100 g).  Again, this kind of increase is easily achievable.

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Healthy whole grains

Refined grains are stripped of their nutrients during processing. In comparison, whole grains retain all of their wonderful nutrients, including fiber, protein, and micronutrients.

Whole grains include:

• hulled barley

• bulgur

• millet

• quinoa

• brown rice

• oatmeal

• popcorn

You can also find whole-grain versions of staples, like bread, cereal, pasta, and flour.

Dose-response studies show that you only need to add a little more to your diet to get health benefits.

Whole grains, heart disease, and cancer

A meta-analysis of 19 studies involving 1,041,692 participants investigated the relationship between whole grains and mortality.

The scientists found an “inverse relationship,” meaning that mortality risk decreases as whole grain consumption increases.

Whole grains and type 2 diabetes

Another review investigated whole grains and the risk of developing type 2 diabetes. They looked at 11 studies, including 463,282 people.

They compared those eating the least whole grains with those eating the most. Those eating the most had a 21% lower risk of developing type 2 diabetes during the study.

Again, they found a dose-response relationship: Each additional 50 g of whole grains per day was associated with a 23% reduced risk of type 2 diabetes.

Nutritious nuts

In the past, nuts were vilified due to their fat content. We now know that most of the fat in nuts — mono- and polyunsaturated fats — are healthy in moderate amounts.

A review and dose-response meta-analysis collated data from 52 studies on nut intake and cancer outcomes.

One walnut (without shell) weighs around 0.1 oz (3 g), making this a highly achievable dietary change.

The studies above show that upping your intake of plants (of any kind), even a little bit, can have long-term health benefits. 

Next, we investigate the other side of the coin: How small reductions in less healthy items can also benefit your health.

Ultra-processed foods and soda

A diet rich in ultra-processed foods (UPFs) is associated with an increased risk of poorer health. Some scientists have investigated whether there is a dose-response relationship.

Recently, it has become clear that not all UPFs are equal — some have no link with poor health outcomes, and some even have positive associations. Others, like soda, have strong evidence of links to poorer health. 

Many studies have identified a negative relationship, including some dose-response analyses.

For instance, a review and meta-analysis investigated soda intake and its links to type 2 diabetes, cardiovascular disease, and mortality risk.

And each extra serving of artificially sweetened beverages was associated with a:

• 13% increased risk of developing type 2 diabetes

• 8% increased risk of cardiovascular disease

• 7% increased mortality risk

What should you do?

So, that was a lot of information, but the conclusions are simple: In the long run, even small increases in the plants you eat and small reductions in UPFs will reduce your risk of disease.

Your changes don’t have to be huge and sweeping. You don’t need to feel restricted and cut out whole food groups. 

Make small changes and build on them. Turn stress-free healthy swaps into healthy habits.

Here’s some inspiration for making simple, healthy changes:

• 10 healthy food swaps from ZOE’s community

• Eat healthy without feeling restricted: Recipes and more

• 24 simple, healthy habits to adopt

• ZOE members’ favorite snacks

• Surprising foods that count toward your 30 plants per week