A colleague recently finished a month-long experiment: trying a vegan diet. Discussing where he'd go from here, he mentioned he was looking for a new challenge, "something else to give up".
Why would we rather cut things out than add them in to our diets? It's a quirk of human nature that seems common. Witness the popularity of programmes for quitting sugar, of low-carb diets, of going paleo or raw or any of their variations.
All involve lists of things you are not allowed to eat. All involve cutting something out - sometimes something we have enjoyed.
There's a psychological quirk in action. Is it that we don't feel we're doing something meaningful unless there's an element of pain and difficulty? Is it that it makes us feel pure and good to give up things that others blithely tuck into? Or is it that people like rules because it eliminates many of the decisions they'd otherwise have to make about what and how to eat?
I think it is possibly a combination of all of these things. We like simple solutions and being told what to eat and what not to eat makes things also quite simple.
We're potentially better off, though, if we can get our heads around the concept of embracing more, rather than eating less.
A study from scientists Auckland University demonstrated this nicely. The study looked at more than 15,000 people in 39 countries, people who already had heart disease.
The researchers found a "Mediterranean" diet, high in fruit, vegetables, fish and unrefined foods,was linked to a lower risk of heart attack and stroke.
Intriguingly, it also found that eating greater amounts of healthy food was more important for them than avoiding unhealthy foods, such as refined grains, sweets, desserts, sugary drinks and deep-fried food.
Eating larger quantities of unhealthy foods was not found to be associated with an increase in adverse cardiovascular events such as heart attacks. This was not what researchers were expecting, but it suggests that focusing on adding healthy foods is possibly more beneficial than cutting out bad ones.
This study has some notable limitations, so it's definitely not telling us we can eat as many lollies as we like as long as we eat plenty of lentils. There are, of course, foods we're better off eating much less of.
But this idea of adding healthy foods works because as we do that, we typically displace other less healthy foods. Eating more vegetables at every meal should naturally lead, over time, to eating less junk food, because we'll be feeling more satisfied and less likely to pick.
As for my colleague, I suggested he think of his next dietary challenge a different way. Adding an extra serving of veges to every meal or adding several meals of legumes a week could have big benefits, minus the denial.
Niki Bezzant is editor in chief of Healthy Food Guide.