Can You Eat More Food and Still Lose Weight?
A new 244-person trial says yes — if you change what fills the plate
Key takeaway: Yes — a 2026 randomized trial of 244 adults found that switching to foods lower in energy density (more produce, whole grains, and legumes) led to real weight loss without cutting portion sizes or counting calories. The vegan group's dietary energy density dropped 30%, and bigger drops meant more weight…
By Dear Sarah · · Updated
Key takeaways
- A 16-week randomized trial of 244 adults with overweight found that a low-fat, plant-based diet led to weight loss with no calorie counting and no portion limits.
- The vegan group's dietary energy density fell by 30%, and every 1 kg of weight lost corresponded to a 0.29-unit drop in energy density.
- Foods high in water and fiber, like vegetables, fruit, and legumes, let you eat a full plate while still taking in fewer calories.
- 91% of participants stayed with the plant-based diet for the full 16 weeks, suggesting it felt sustainable rather than restrictive.
- This finding echoes separate Harvard research on menopause weight gain, where the same plant-forward eating pattern also came out ahead.
Yes — a randomized trial published this month found people lost weight without eating less food, without counting a single calorie, and without ever feeling hungry. The trick wasn't restriction. It was swapping in foods that are lower in energy density, so you can eat a full plate and still take in fewer calories.
What did the new study actually find?
Researchers at the Physicians Committee for Responsible Medicine put 244 adults with overweight through a 16-week randomized trial, published August 6 in JAMA Network Open. Half were told to eat a low-fat, plant-based diet — fruits, vegetables, whole grains, legumes — with no calorie limit and no portion control. The other half changed nothing. The vegan group's dietary energy density dropped by 30%, and the more it dropped, the more weight people lost: every 1 kg lost tracked with a 0.29-unit drop in energy density. Ninety-one percent of participants stuck with it for the full 16 weeks, which is itself worth noting — this wasn't a diet people white-knuckled through and quietly abandoned by week six.
Dr. Hana Kahleova, the study's lead author, put it simply: "You don't have to eat less. You can eat more food, feel full, and still lose weight by choosing foods that are naturally lower in energy density." Plant foods carry a lot of water and fiber for their calorie count, so your stomach fills up on volume before you've eaten yourself into a calorie surplus. "This isn't about willpower or smaller portions," she added. "It's about choosing foods that naturally deliver fewer calories in every bite." That distinction matters — it moves the responsibility off your self-control and onto the actual composition of your plate.
Why this matters for you, specifically
If you've ever downloaded a calorie-tracking app, used it religiously for nine days, then quietly deleted it out of sheer exhaustion, you already know the problem with most weight advice: it asks you to out-discipline your own hunger, forever, with no end date. That's not a personal failing. It's a design flaw in the advice itself. This is the research that backs up what a lot of women have felt in their gut but couldn't point to a study for — that eating less isn't actually the lever that works long-term. Comparing intermittent fasting to calorie counting turned up the same pattern: the eating style that survives real life is the one with the fewest rules to break.
It also lines up with what Harvard found when it tracked almost 40,000 women through menopause — the diets that actually blunted weight gain were plant-forward ones built around produce, whole grains, and legumes, not the lowest-calorie ones on paper. Two different research teams, two different life stages, landing on the same shape of answer: what you eat matters more than how little of it you eat. And if you've been looking for a lower-effort way to shift what's on your plate without overhauling every meal, this one small protein swap is a good place to start alongside it.
One thing to try today
You don't have to go fully plant-based to use this. At your next meal, build the plate around something with water and fiber already in it — a big handful of greens, a bowl of soup, roasted vegetables, a piece of fruit — before you add the rest. You'll likely eat just as much food and walk away just as full, on fewer calories, without doing any math or feeling like you're being punished for wanting to eat.
Quote to sit with
"Caring for myself is not self-indulgence, it is self-preservation, and that is an act of political warfare." — Audre Lorde
💌 Sarah
Frequently asked questions
Do you have to go fully vegan to lose weight with this method?
No. The study tested a fully plant-based diet, but the underlying mechanism — eating more low-energy-density foods like vegetables, fruit, and legumes — works on a spectrum. Adding more of those foods to any meal pattern lowers its overall energy density.
What is dietary energy density?
It's the number of calories packed into a given weight of food (kcal per gram). Foods with a lot of water and fiber, like vegetables and fruit, have low energy density, so you can eat a larger amount of them for fewer calories.
Does this mean calorie counting doesn't work?
Calorie counting can work, but this research points to an easier path for a lot of people: changing what's on the plate rather than tracking every bite. Participants in the study weren't given any calorie targets and still lost weight.
How much weight did people lose in the study?
The published analysis focused on the relationship between energy density and weight change rather than a single average number, finding that a 1 kg weight loss corresponded to a 0.29-unit decrease in dietary energy density across the 16 weeks.
Sources
- Vegan Diets and Dietary Energy Density: A Secondary Analysis of a Randomized Clinical Trial — JAMA Network Open
- Low-Fat Vegan Diet Cuts Dietary Energy Density by Nearly a Third, Helping Explain Weight Loss, New Study Finds — Physicians Committee for Responsible Medicine
- Low-fat vegan diet helps people lose weight without eating less — ScienceDaily
Keep reading
- Does Creatine Help With Depression? What New Research Shows — A new review of five clinical trials on creatine and depression found real promise — but only in the trials that studied women. Here's the honest read.
- Why Healthy Meals Are Important — Healthy meals fuel your days, mood, and energy — small tasty swaps that add up without feeling restrictive.
- What's the Best Diet for Menopause Weight Gain? — New Harvard research followed nearly 40,000 women through menopause and found the diets that actually blunted weight gain. Here's what worked.
- Can Small Diet Changes Really Lower Your Heart Disease Risk? — A new 20-year study followed 67,000 women. The takeaway isn't perfection — it's what's on your plate most days.