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I recently asked several of my medical-nutrition colleagues if they could only track one nutrient/food measure, what would it be?

A few said carbs, as they were aiming for low carb intake, others said fat, as they had a specific fat level they recommended daily. I heard magnesium, as it is a super important mineral and 70% of people don’t get enough. Even omega-3 fats came up, as they have a very important anti-inflammatory role.

These are all very important nutrients to monitor, but when I look at what single indicator could have the most beneficial aspect on your health, I would pick…………………FIBER.

I’d pick fiber. Why?

  • First, eating fiber makes you full and satisfied. From the National Weight Loss Registry, a study that tracks people who have lost more than 10% of their body weight and kept the weight off long term, the single nutrient that best predicts “successful” weight loss is fiber intake.
  • Eating fiber improves blood sugar control and reduces insulin resistance. Basically, fiber binds sugars in your gut and releases them slowly into your bloodstream, rather than a blood sugar spike upwards stimulating excessive insulin production.
  • Eating fiber binds to cholesterol and lowers LDL cholesterol levels. Eating more fiber from vegetables, fruits, beans and nuts also increases the size of the cholesterol particles, yielding big, fluffy LDL and HDL cholesterol that form less arterial plaque.
  • Consuming the right fiber improves other cardiovascular risk factors too. Eating more fiber improves blood pressure control, decreases fibrinogen (a risk factor for blood clots) and lowers inflammation levels as well.
  • Fiber is also great for helping to detoxify the body. Heavy metals and toxins bind to fiber and are eliminated through your waste.

Is There Good and Bad Fiber?

Fibrous foods come from carbs. The key is that you want low-glycemic load fiber sources, as in foods that don’t raise your blood sugar levels.

All fruits (except a banana, and processed fruits—like juice or dried or canned fruits) have a low glycemic load, meaning they don’t increase blood sugar levels significantly when eaten in a normal 1 cup portion.

Eating vegetables has a very minimal impact on blood sugar levels, except for the potato, which has a high glycemic load; sweet potatoes and little-boiled potatoes have a medium glycemic load and are better choices than mashed potatoes or baked potatoes.

Beans and nuts both have a low glycemic load. In fact, eating beans with rice or corn, or other high glycemic load foods will decrease their overall impact on blood sugar control.

Sources of fiber that increase your blood sugar levels should be avoided, or at least limited to occasional small portions. These include potatoes, rice, corn, and grains, especially any grain that has been processed into flour; consuming grain flour, including whole wheat flour, has the same impact on your blood sugar levels as if you ate table sugar instead.

Which Is Better, Soluble or Insoluble Fiber?

Insoluble fiber is found in whole grains, fruits, and vegetables. Eating more insoluble fiber prevents constipation, and is loaded with nutrients.

Soluble fiber is found especially in citrus fruits, vegetables, nuts, and oats. Consuming more soluble fiber improves cholesterol and blood sugar levels.

The bottom line is that you want both soluble and insoluble fiber, and you get both from eating a combination of vegetables, fruits, beans and nuts.

How Much Fiber Should You Get Daily?

30 grams of fiber is the minimum daily goal for adults. That is about 10 servings of fruits, vegetables, beans, and nuts.

As an example, to get 30 grams in a day, you would want to eat:

  • 3 cups of vegetables (three 4-ounce/110 gram servings)
  • 2 fruits, such as 1 cup of berries or cherries (4-5 ounces or 120 grams) plus one apple, orange, or pear
  • ½ cup of cooked beans
  • 2 handfuls of nuts (2 ounces or 60 grams)
  • 1 ounce of dark chocolate (30 grams)

If you don’t reach 30 grams daily, you can also take a fiber supplement in a smoothie or drink. A few examples of good sources of fiber include:

  • Fiber-Blend                     6 grams (per tablespoon)
  • Psyllium husks (1 tablespoon)          4.5 grams
  • Flaxseed (1 tablespoon ground)      2.5 grams

Sample Fiber Chart:

Below is a sample table with fiber sources. Pick the foods you like the best and aim to eat at least 30 grams of fiber every day.

I hope that you feel motivated to eat more fiber every day.

I wish you the best of health!


Steven Masley, MD, FAHA, FACN, FAAFP, CNS