#077 The Easiest Diet to Lose Weight: Focus on Fiber

The Easiest Diet to Lose Weight: Focus on Fiber

Have you ever tried to drop a few pounds?  Did you struggle to follow a complex new way of eating?  If so, please read on as this article is just for you.

This is exactly the question researchers sought to answer in this new study that was just published in the prestigious Annals of Internal Medicine.  How well would just encouraging people to eat more fiber compare to the very rigid American Heart Association (AHA) Diet?

“Eat More Fiber” versus AHA Diet

In this study, researchers recruited 240 overweight people who also had diabetes, high blood pressure, or high cholesterol and randomized them to either eat more fiber or follow the AHA Diet for 1 year.

“Eat More Fiber” Study Group

I should note that the “eat more fiber” group really did not eat that much fiber.  They were only encouraged to eat 30 grams of fiber each day which is the bare minimum amount of fiber that any adult should eat.

At the end of the study, the “eat more fiber” study group really did not do that good of a job.  They were only able to average a measly 23.5 grams of fiber daily which only represented a 4.7 gram improvement from what they were eating before the study started.

To put things into perspective, a 4.7 gram improvement in fiber is the equivalence of eating 1 more apple since an apple has about 5 grams of fiber. However, given that the average American only averages about 15 grams of fiber each day, 23.5 grams of fiber could be considered a significant accomplishment.

AHA Diet Study Group

In contrast, the AHA Diet was very strict.  Here is the AHA Diet as taken from the AHA website.

1. Eat fruits, vegetables, nuts, and whole grains.

2. Eat lean meats, including fish at least twice weekly.

3. Eat fat-free or low-fat dairy products.

4. Cut back on partially hydrogenated vegetable oils to reduce trans fat.

5. Keep saturated fat to no more than 5-6% of total calories.

6. Cut back on beverages and foods with added sugars.

7. Keep sodium less than 2,400 mg per day.

8. Drink alcohol in moderation.

Interestingly, by following this very complex AHA diet, study participants also increased their fiber intake.  However, on the AHA diet, people only increased their fiber intake by 1.3 grams per day to a total fiber average of 20.8 grams.  Thus, in comparison to the “eat more fiber” group, the AHA group ate about a half an apple less fiber each day.

Key Findings of the Eat More Fiber vs. AHA Diet Study

What happened after 1 year of following these diets?  I should note that study participants were not encouraged to exercise.  Thus, any changes were based only on the diet they were randomized to.  Here are the key findings:

1. The “Eat More Fiber” Diet was just as effective at weight loss as the complex AHA Diet.

2. 90% of the “Eat More Fiber” group could stick with their diet 1 year later.

3. The “Eat More Fiber” group lost 1 pound of body weight for each extra gram of fiber they averaged each day.

4. Eating 5 extra grams of fiber each day reduced daily calories by 200 per day.

These findings are really very interesting.  Adding just 5 more grams of fiber each day reduced caloric intake by 200 calories and resulted in a sustained weight loss that 90% of study participants could do.  This really has to be the easiest diet ever to follow.  However, the one thought that kept coming back into my mind was what would the results have been if the “eat more fiber” group really did eat more fiber?

Medical Benefits of a High Fiber Diet

A high fiber diet has additional benefits of lowering blood pressure, blood sugar, and cholesterol.  In addition, fiber causes people to feel full and decreases the hunger hormones.

Despite these proven medical benefits of increased dietary fiber, these findings were not observed in this study.  I suspect that this was because study participants only increased their fiber intake by 5 grams each day.

The Traditional High Fiber Diet of China’s Longevity Village

The findings of this study are right in line with our research in China’s Longevity Village.  In this village, everything the villagers ate was high in fiber except the fish which they ate 1-2 times each week.

Villagers ate fruits and vegetables with every meal.  They also ate nuts, seeds, legumes, and whole grains every day.  All of these foods are extremely high in fiber and nothing was processed.  Sugar was just not a part of their diets.

After we returned back to the U.S. following our first visit to the Village, this was one of my guiding dietary principles as well.  I was overweight and all of the diets I had previously tried did not work for me.  Desiring to model my diet after those in the Village, I simply required that everything I ate be high in fiber with the exception of fish.

Almost overnight my daily fiber intake went from around 15 grams a day to an average of 70 grams of fiber each day.  Within just a few months my weight dropped 30 pounds without ever experiencing hunger from these changes.

To this day I still average 70 grams of fiber each day and I have easily kept the weight off for 3 years.  To track my daily dietary fiber intake I have used the app Lose It!

How to Increase Fiber in 6 Simple Steps

Here are my 6 simple tips to increase the fiber in your diet.  If you are not used to eating fiber you will need to gradually increase your fiber intake over time to avoid any gastric distress.

1. With the exception of fish, wild meats or eggs, try to make everything you eat be high in fiber.

2. I encourage my patients to get 9 servings of fruits and vegetables each day (20-25 grams of fiber).

3. I encourage my patients to get at least 1 serving of legumes each day (10-20 grams of fiber).

4. I encourage my patients to get at least 1 serving of nuts or seeds each day (2-7 grams of fiber).

5. Only eat real whole grains such as quinoa, brown rice, or coarse “flourless” wheat if you are not gluten sensitive, etc. (10-20 grams of fiber)

6. Track your fiber with an app like Lose It!


As with all of my articles, do not self diagnose or treat based on anything that you have read.  Always discuss health changes with your physician first.



Disclaimer Policy: This website is intended to give general information and does not provide medical advice. This website does not create a doctor-patient relationship between you and Dr. John Day. If you have a medical problem, immediately contact your healthcare provider. Information on this website is not intended to diagnose or treat any condition. Dr. John Day is not responsible for any losses, damages or claims that may result from your medical decisions.

  1. Here’s a book I’ve found interesting and valuable, related to fiber:

    The Save Your Life Diet
    by Dr. David Reuben, M. D.
    Copyright 1975