Officially known as the “Daniel Fast”, the diet sees people eat fruit, vegetables and whole grains. Followers only drink water and avoid eating meat, fish, bread and any sweetened or processed foods.
The eating plan is based on that followed by the Old Testament prophet, Daniel.
Susan Gregory, author of "The Daniel Fast", explained that the plan is based on his recorded fasting experiences.
She explains that Daniel was among a group of men captured by Babylon and that King Nebuchadnezzar of Babylon wanted the men to be in top condition - so insisted they eat the same food as he ate.
But when Daniel was served this food, he refused it, he felt the food had not been prepared according to Jewish standards.
Ms Gregory says, he vowed to eat just foods grown from seeds and drink only water.
Later, Daniel fasted again while seeking God's word on the future of Israel and described this fast as involving no meat, wine or leavened bread.
Daniel 10:3 states: "I ate no delicacies, no meat or wine entered my mouth, nor did I anoint myself at all, for the full three weeks."
These biblical descriptions of Daniel’s fasts form the basis of the new eating plan.
Ms Gregory, who described the Daniel Fast as a "vegan diet with even more restrictions", says following the diet involves avoiding caffeine, chemicals and sugar and, as a result, it can ease headaches, leg cramps and fatigue.
She added it can also cause people's cholesterol levels to fall and their blood sugar levels to balance out.
The author adds that the diet often leads to weight loss and "a general feeling of wellbeing".
However she adds that, while the diet is a very healthy way to eat, people with health problems might need to modify it.
For example that people with diabetes might need to eat more carbohydrates and that pregnant women and breastfeeding mothers might need to add fish, chicken and cheese.
Sarah Neumann, from Michigan, tried the Daniel Fast as a religious exercise and without considering the weight loss that could go with it.
She told that she initially struggled with it when she eating in restaurants or with friends.
However, she says she lost weight while on the diet and she still has a healthier diet as a result.
"Since the experience I've lost a lot of weight just from learning how to have more self-control" she said.
But the nutritionist Zoe Harcombe is unconvinced by the health benefits of following the diet. She explained that the health impacts it would depend on how long someone follows it for.
However the nutritionists say it could lead to shortages in many vital vitamins as Vitamin A, Vitamin D, Vitamin E and Vitamin B12.
- Tags: God diet Prophet Daniel's Old Testament prophet Susan Gregory The Daniel Fast Babylon King Nebuchadnezzar_of_Babylon Israel Vegan_diet Sarah Neumann Michigan Zoe Harcombe Vitamin A Vitamin D Vitamin E Vitamin B12.