When it comes to healthy meals, most of us — 75 percent — say our choices are good, very good or excellent. But how much attention do we pay to the snacks we grab? Probably not that much, a new study finds.

The research looked at the snacking habits of 854 people from the ZOE PREDICT study, a collaboration of researchers and scientists from Massachusetts General Hospital, Stanford Medicine, Harvard T.H. Chan School of Public Health, and King's College London.

PREDICT stands for “Personalized Responses to Dietary Composition” and is part of a series of large-scale, nutritional science studies designed to understand individual metabolic responses to different foods. For this study, the researchers investigated snacking.

A little over a quarter of the people participating in the study said that although they ate healthy meals, their snacks were poor quality.

Snacking in itself isn't bad for us — as long as the snacks are healthy. In fact, the study showed that participants who frequently ate high quality snacks like nuts and fresh fruits were more likely to have a healthy weight compared to those who didn't snack at all, or compared with those who snacked on unhealthy foods.

“Considering 95 percent of us snack, and that nearly a quarter of our calories come from snacks, swapping unhealthy snacks such as cookies, crisps [chips] and cakes to healthy snacks like fruit and nuts is a really simple way to improve your health,” senior author Sarah Berry, a researcher at Kings College London, said in a press statement.

People in the United States vary only slightly from their United Kingdom counterparts when it comes to snacking. Ninety percent of U.S. adults report eating one or more snacks on any given day, in the UK, it's 95 percent.

Snacking itself is not the main problem — what we snack on is the more important issue. Opting for good quality snacks not only makes us feel less hungry, it also helps our maintain metabolic health, enabling our bodies to be better able to respond to food in a beneficial way. This in turn reduces our risk of unhealthy conditions such as obesity, type 2 diabetes, heart disease, stroke and kidney disease.

A little over a quarter of the people participating in the study said that although they ate healthy meals, their snacks were poor quality. The greatest contribution to calorie intake were cakes and pies (14 percent) breakfast cereals (13 percent) ice cream and frozen dairy desserts (12 percent) donuts and pasties (12 percent) candy (11 percent) and cookies and brownies (11 percent).

It's not only what you snack on, but also when you do it.

While 11 percent of participants snacked on nuts and seeds, the majority of snackers opted for highly processed and sugary treats. These choices not only left participants feeling hungry, but the researchers reported the volunteers had a higher BMI (Body Mass Index) and higher levels of unhealthy triglycerides which contribute to obesity, cardiovascular diseases and stroke.

It's not only what you snack on, but also when you do it. An analysis of the timing of snacking showed that munching after 9 pm was associated with poorer blood markers compared to all other snacking times. What's more, these late night snackers tended to go for foods which were high in fat and sugar.

What are some healthy snack substitutes? The Centers for Disease Control suggests:

  • Fruit such as apples, oranges, bananas, grapes and canned fruit without added sugars.
  • Washed and chopped celery, carrots and cucumbers.
  • Low-fat and fat-free yogurt without added sugars, milk and low-fat cheeses.
  • Whole-grain crackers and breads.
  • Proteins such as nuts and seeds.

The study is published in the European Journal of Nutrition.