Choosing certain foods may lead to fewer calories consumed – even with larger portion sizes, according to a novel study. Here’s what the research reveals.
The common advice to eat less to lose weight may be challenged by new research. A recent investigation by the University of Bristol suggests that prioritizing whole, unprocessed foods can actually lead to consuming *more* food while still taking in fewer calories compared to a diet dominated by highly processed options. This finding has implications for how we approach weight management and dietary recommendations.
Researchers Re-Analyze Data from a Landmark Nutrition Study
For their operate, published in The American Journal of Clinical Nutrition, scientists led by Professor Jeff Brunstrom re-examined data from a clinical study conducted in 2019 by the U.S. National Institutes of Health. The original study involved 20 participants who each spent two weeks consuming either exclusively unprocessed or exclusively highly processed foods – and were allowed to eat as much as they wanted.
The surprising result of the re-analysis: Participants who ate a diet of whole, unprocessed foods consumed around 57 percent more food by weight than the group consuming highly processed foods. Despite this, they averaged 330 fewer calories per day.
Fruits and Vegetables Over Steak and Pasta
What explained this difference? Researchers found that participants on the unprocessed food diet instinctively gravitated towards fruits and vegetables – sometimes consuming several hundred grams per meal. Calorie-dense options like meat, pasta, or butter were less frequently included in their meals.
Study leader Jeff Brunstrom explained in a press release from the University of Bristol: “It’s fascinating to see that people, when offered unprocessed options, intuitively select foods that balance enjoyment, nutritional value, and satiety – while simultaneously reducing overall energy intake.” He added that our food choices aren’t random, stating, “we actually appear to make much smarter decisions than previously assumed when food is presented in its natural state.”
Innate “Nutrition-Related Intelligence” as an Explanation
The researchers propose a type of built-in “nutrition-related intelligence” – an inherent ability to favor foods rich in micronutrients over calorie-dense alternatives. They call this mechanism “Micronutrient Deleveraging”: the body prioritizes foods high in vitamins and minerals, which automatically leads to lower calorie intake when consuming whole, natural foods.
This mechanism appears to be disrupted with highly processed foods. The reason: many ultra-processed foods are fortified with vitamins and simultaneously deliver a high number of calories. Some of these are also on the list of 11 foods that shouldn’t be on your plate.
Overeating Isn’t the Core Problem
Professor Brunstrom emphasized that overeating itself isn’t the primary issue. Rather, the composition of available food influences our decisions. Highly processed products steer people toward more calorie-dense options, which can contribute to excessive energy intake – and potentially obesity.
Critical Assessment of the Study and Limitations
The study is based on a re-analysis of existing data and includes only 20 participants. Further research is needed to confirm whether the described nutrition-related intelligence is innate or influenced by social factors. Nevertheless, the findings provide important insights that suggest choosing whole, unprocessed foods can be an effective strategy for weight control.
Planetary Health Diet: the Guide PDF
Here you can download the PDF “Planetary Health Diet” for free download.
Practical Tips: How to Achieve a Whole-Food Diet
Those looking to implement the study’s findings in their daily lives can follow the recommendations of the German Nutrition Society (DGE). The DGE advises a balanced, predominantly plant-based diet with at least five servings of fruits and vegetables per day. Legumes such as lentils, beans, and peas, as well as nuts, are particularly highlighted in the current DGE recommendations.
Specifically, this means:
- More Fruits and Vegetables: At least three servings of vegetables and two servings of fruit per day – preferably seasonal and local.
- Choose Whole Grains: Select whole-grain varieties of bread, rice, and pasta.
- Incorporate Legumes Regularly: Lentils, Chickpeas, or beans provide plant-based protein and promote satiety.
- Nuts as a Snack: A handful of unsalted nuts per day provides healthy fats and essential micronutrients.
- Reduce Processed Foods: Consume ready meals, soft drinks, and industrially produced snacks as infrequently as possible.
All of these tips are embedded within the Planetary Health Diet. This provides a scientifically sound nutritional approach that combines health and sustainability. Registered users can download our free PDF guide to the Planetary Health Diet – with practical tips and concrete recipe ideas.
