How To Lose Weight While Eating as Much Food As You Want

silver fork and knife on plate

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It would be so easy to lose weight if we could eat as much food as we want and still lose weight. When we think about weight reduction we often think about a low amount of food on our plate. As a medical doctor certified in lifestyle medicine I have followed the research on weight loss for many years. Changing the food can certainly change your weight. But did you know that you do not have to sacrifice the amount of food in order to reduce weight?

Eating a low fat version of the whole food plant based diet can help you lose weight even if you eat as much food as you want.

In this blog post we will look into two fascinating studies that show that you can lose weight even if you give no thoughts to how much food you eat.

What is a low fat whole food plant based diet?

A low fat whole food plant based diet is based on the following principles:

  • Whole foods: This means natural foods that are not processed to a large extent.
  • Plant based: The food in this diet come exclusively from plants. Ingredients from animals such as meat, dairy and eggs are avoided.
  • Low in fat: This diet limit the intake of nuts, seeds, oils, and other fatty plant foods. Typically the diet contains 7-15% of daily calories from fats.
macro shot of vegetable lot

What are the benefits of a low fat whole food plant based diet?

A low fat whole food plant based diet is a diet high in nutrients but low in calories. A whole food plant based diet has many health benefits and is the recommended diet by the American College of Lifestyle Medicine

“The American College of Lifestyle Medicine recommends an eating plan based predominantly on a variety of minimally processed vegetables, fruits, whole grains, legumes, nuts and seeds” – ACLM

In addition to help with weight loss a whole food plant based diet has demonstrated reversal of ischaemic heart disease, improvements in glycaemic control, long-term acceptability and sustainability, and reduction of prostate-specific antigen in biopsy-proven low-grade prostate cancer. A whole food plant based diet is also better for the environment, causing less emission of green house gases.

LIVE LIGHTLY – THE SUSTAINABLE WEIGHT LOSS SYSTEM focusing on a whole food plant based diet

Why a low fat plant based diet is excellent for weight loss

There are several reasons why a low fat plant based diet reduces weight:

  • Low in calories
  • High in fiber
  • High in volume and weight
  • High in nutrients 

Evidence from studies

The BROAD study

WHAT: The BROAD study was a randomized controlled trial that was published in 2017. According to the authors the study showed a greater weight reduction with a low fat whole food plant based diet than any other dietary strategies to that date where people could eat freely and did not have to exercise.

WHO: The participants of the study where people 35-70 years of age with overweight or obesity. The participants who were in the intervention group received

THE FOOD: In this study the intervention group ate a low fat version of a whole food plant based diet.

  • Whole grains
  • Legumes
  • Vegetables
  • Fruits
  • Starches such as potatoes, sweet potato, bread, cereals and pasta in order to satisfy the appetite.
  • 50 μg daily vitamin B12 (methylcobalamin)


  • Refined oils (e.g. olive or coconut oil) and
  • Animal products (meat, fish, eggs and dairy products).
  • High-fat plant foods such as nuts and avocados, and
  • Highly processed foods.
  • Minimize sugar, salt and caffeinated beverages.


  • Participants were advised to eat until satiation
  • No restriction on total energy intake
  • Participants were asked to not count calories

RESULTS: After 6 months the average BMI was down 4.4 in the intervention group and 0.4 in the control group. At 12 months BMI was down 4.2 in the control group and 0.6 i the control group.

In actual kg the participants in the intervention group lost on average about 12 kg at 6 and 12 months. In addition the use of medication was significantly reduced in the participants eating a low fat whole food plant based diet. To the authors knowledge there was to that date (2017) no other studies that have achieved greater weight loss over a 6 to 12 months period without including regular exercise or restricting total caloric intake.

The researchers concluded that a whole food plant based diet is a safe and effective strategy to lose weight, and the main advantage is that it is possible to eat freely without restricting the amount of food.

Study 2: How to eat 5kg food daily and still lose weight

In 2001, David Jenkins, one of the leading scientists on plant based diets conducted a study with fascinating results. The main focus was to examine to what extent a very high fiber diet could reduce cholesterol levels in the blood.

The scientists tested three different diets:

  • A high-vegetable, fruit, and nut diet with very high fiber (55 g/1,000 kcal)
  • A starch-based diet containing cereals and legumes (early agricultural diet)
  • A low-fat diet (contemporary therapeutic diet).

All three diets where composed individually so that the participants would not lose weight (mean intake, 2,577kcal/d).

The amount of food that was eaten in the high vegetable, fruit and nut diet was enormous, about 5kg a day. As you may expect the participants eating the high-vegetable,-fruit-and-nut diet struggled to eat all of the food they were served.

Here is an example of the 5kg menu that the participants ate during one day:

32 g Filberts503 g Brussel sprouts503 g Broccoli
302 g Raspberries302 g Okra302 g Eggplant
302 g Honeydew302 g Green peas302 g Carrots
302 g Banana322 g Mushrooms252 g Snow peas
 32 g Filberts32 g Filberts
 322 g Plums302 g Strawberries
  604 g Tangerines

Although it was a whole food plant based diet it was not particularly low in fat (22% of daily calories from fat)


After one week the high vegetable, fruit and nut diet had reduced LDL-cholesterol by 33%.

With the group eating a high vegetable, fruit and nut diet there was a trend towards losing weight, about 500g after 2 weeks, though not statistically significant. However, the study showed that if you really want to eat all the food you can, you can do that without gaining weight. Although a nutritious diet, we do not recommend starting on a 5kg-food-a-day diet. Such a large amount of food may cause various challenges. For instance, the daily fecal bulk was more than 1kg.


If you want to lose weight without limiting the amount of food that you eat, a low fat whole food plant based diet may be a safe and nutritious solution. While this diet is low in calories, it is high in nutrients. Research has demonstrated that it is one of the most effective dietary weight loss strategies. If you are overweight or obese a low fat whole food plant based diet may help you lose about 12kg in about 6 months without any restrictions on the amount of food you eat.


Are you ready for a new dietary start and do not know how to prepare whole food plant based dishes I have provided a link below to an electronic book with 300 plant based dishes featuring a variety of plant based meals, high protein salads, plant based sandwich recipes, and more.

You may also want to check out more helpful tips for weight loss in our Lifestyle Prescription Database.


Wright, Nicholas, et al. “The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease or diabetes.” Nutrition & diabetes 7.3 (2017): e256-e256.

Jenkins, David JA, et al. “Effect of a very-high-fiber vegetable, fruit, and nut diet on serum lipids and colonic function.” Metabolism-Clinical and Experimental 50.4 (2001): 494-503.

Allan Fjelmberg, MD, MPH, DipIBLM

As a Norwegian based medical doctor certified in Lifestyle Medicine he currently serves as the medical director of Skogli Health and Rehabilitation Center, Lillehammer. Through consultations, presentations, articles and other public health-related activities, he motivates people to utilize the potential that a healthy lifestyle has both in prevention and treatment of disease.

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