The F-Factor Diet

What is the F-Factor Diet?

The F-Factor, created by celebrity dietitian Tanya Zuckerbrot,  is a very high-fiber diet (the "F" stands for fiber). This means eating fruits, non-starchy vegetables, legumes and select whole grains like high-fiber cereal and bulgur. Since your digestive system cannot break down fiber into energy, it helps make you feel full.

In addition, you also need to eat lean proteins and some fats. While the diet does not limit the number of a dieter's calories per day, the recommendations for other foods ultimately limits overall calorie intake.

The F-Factor Diet consists of three phases:

Phase one: this phase typically lasts two weeks and requires dieters to eat at least 35 grams of fiber per day. It also entails eating fewer than 35 grams of net carbs (i.e.total carbs minus fiber).

Phase two: still sticking with the high fiber count, but net carbs increase to 75 grams per day until you have lost as much weight as you want to lose.

Phase three: known as the maintenance phase, dieters eat 125 grams of net carbs per day but stick with the high fiber count.

In all three phases, dieters are also encouraged to get 30% of their calories from fat, which is around 33 grams per day.  The diet also encourages high protein intake—between 10 and 14 ounces of lean protein per day for women. 

Lastly, water is a huge part of the F-Factor Diet, because fiber needs water to work. The dieters need to drink three liters, or more than 12 cups of water a day. 

Conversely, the F-Factor cautions against eating high-fat meat and dairy, and encourages dieters to avoid saturated fats and added sugar. Alcohol is not off limits and that a 4-ounce glass of wine contributes 2 net carbs to your daily carb count.

However, the diet is far more likely to cause long-term harm than do short-term good of losing weight:

• It is not nutritionally-sound because the total energy looks to fall below what most adults would need to eat in a day. It provides too few calories to be healthy for most people.  This is because in one of the previous starvation studies, it was found that after six months on a low-calorie diet, the subjects experienced significant drops in strength, body temperature, heart rate and sex drive, as well as increased levels of depression, irritability, and fatigue. Worse, they became obsessed with food, dreaming about it often, and talking and reading about it constantly. A 2015 review study published in the International Journal of Obesity explains that rapid weight loss can actually trigger physiological changes that make it really hard to lose more weight and actually promote weight gain, including fewer calories burned, less fat oxidation, increased production of hunger hormones and decreased production in hunger hormones.

• While fiber is good for you, too much fiber can lead to some nasty side effects such as causing GI disruptions like bloating, abdominal pain and constipation, among other symptoms.

• Also, getting too full from fiber-rich foods means you might not have room for adequate protein, fat and starchy carbohydrates.