Daniel Fast Published Research

We first began study of the Daniel Fast in September 2009. To our knowledge, no other group has published research pertaining to this form of fasting. However, studies have been published regarding other forms of religious fasting (Please click here for a summary of this work), in addition to work pertaining to plant-based diets.

While we currently have other studies in progress (see Ongoing Research), only those studies indicated below are presently available in peer-reviewed manuscript format.

Bloomer RJ, Kabir MM, Canale RE, Trepanowski JF, Marshall KE, Farney TM, Hammond KG. Effect of a 21 day Daniel Fast on metabolic and cardiovascular disease risk factors in men and women. Lipids Health Dis. 2010 Sep 3;9:94.


In this initial study of the Daniel Fast, 43 subjects (13 men; 30 women; age range: 20-62 years) completed a 21 day Daniel Fast, in accordance with detailed guidelines provided by the investigators. All subjects purchased and prepared their own food—this is important to note, as some laboratory-based studies use prepackaged food or research kitchens in order to enhance compliance to the eating plan.

Following initial screening, subjects were given one week to prepare for the fast. They were provided with detailed instruction sheets regarding which foods were allowed and which foods were disallowed, as well as a basic recipe guide. Subjects then reported to the lab for their pre-intervention assessment (day 1 of the fast). After the 21 day fast, subjects reported to the lab for their post-intervention assessment (day 22). For both visits, subjects reported in a 12 hour fasted state, performing no strenuous physical activity during the preceding 24-48 hours. This was important, as we know that both eating and exercise could impact our chosen outcome measures (e.g., cholesterol, insulin, glucose). At each visit, subjects’ mental and physical health, resting heart rate and blood pressure, and anthropometric variables such as circumference, body weight, and body composition were measured. Blood was collected for determination of clinical measures such as complete blood count, comprehensive metabolic panel, lipid panel, insulin, and C-reactive protein (a marker of systemic inflammation). Subjects’ self-reported compliance, mood, and satiety (i.e., feeling of fullness and satisfaction following eating) in relation to the fast were also recorded. Diet records were maintained by all subjects during the 7 day period immediately prior to the fast (representing subjects’ usual intake) and during the final 7 days of the fast.


Subjects’ compliance to the fast was excellent and measured at nearly 99%. On a 10 point scale (0 being the worst and 10 being the best), subjects’ mood and satiety were both 7.9. Many subjects also reported greatly improved knowledge related to food composition with regards to macro- and micro-nutrients, as well as additives and preservatives contained within foods. Favorable effects were noted in many variables, with those of greatest interest being the following:

Total cholesterol: the primary “blood fat” and a known major risk factor for cardiovascular disease; elevations in total cholesterol may lead to atherosclerosis—potentially resulting in heart attack or stroke.

LDL-cholesterol: the so called “bad” cholesterol and a known major risk factor for cardiovascular disease; as with total cholesterol, elevations in LDL-cholesterol may lead to atherosclerosis—potentially resulting in heart attack or stroke.

Systolic blood pressure: the pressure exerted on the arterial walls during the contraction phase of the cardiac cycle and a known major risk factor for cardiovascular disease.

Diastolic blood pressure: the pressure exerted on the arterial walls during the relaxation phase of the cardiac cycle and a known major risk factor for cardiovascular disease.

Insulin: a hormone involved in the control of blood sugar; higher fasting insulin levels are associated with type 2 diabetes.

HOMA-IR: the homeostatic model of insulin resistance; lower values may indicate improved insulin sensitivity (an improved ability for the hormone insulin to work with its receptor and ultimately clear sugar from the blood).

High sensitivity C-reactive protein: an acute phase protein which serves as a marker of systemic inflammation; increased inflammation may be an associated risk factor for cardiovascular disease (in particular when combined with other known risk factors).


A 21 day period of modified dietary intake in accordance with the Daniel Fast by men and women 1) is met with excellent compliance, 2) is well-tolerated, 3) serves to educate individuals regarding food choices and the composition of a variety of foods, and 4) improves several risk factors for metabolic and cardiovascular disease.

Bloomer RJ, Kabir MM, Trepanowski JF, Canale RE, Farney TM. A 21 day Daniel Fast improves selected biomarkers of antioxidant status and oxidative stress in men and women. Nutr Metab (Lond). 2011 Mar 18;8:17.


Dietary modification via caloric and nutrient restriction is associated with multiple health benefits, some of which are related to an improvement in antioxidant capacity and a decrease in the production of reactive oxygen species (ROS), or what are known as “free radicals.” The Daniel Fast includes food intake rich in fruits, vegetables, whole grains, legumes, and nuts—all considered to be healthy foods, with many foods rich in antioxidants. Although plant-based diets have been studied previously, most investigations have focused on the measurement of blood lipids such as cholesterol. Moreover, although such diets prohibit animal product consumption, they allow the consumption of processed and refined foods as well as foods that contain additives and preservatives—items that are not allowed within the Daniel Fast guidelines.

Based on the above, the purpose of this investigation was to determine the effect of a 21 day Daniel Fast on biomarkers of antioxidant status and oxidative stress. Subjects reported to the lab on day one of the fast and again on day 22 (the morning following the completion of the fast), to provide a blood sample. For both visits, subjects reported in the morning in a 12 hour fasted state, without performing strenuous physical activity during the preceding 48 hours (as such activity may have impacted our chosen outcome measures). At each visit, blood was collected for determination of oxidative stress biomarkers (malondialdehyde [MDA], hydrogen peroxide [H2O2], and nitrate/nitrite [NOx]), as well as antioxidant capacity (Trolox Equivalent Antioxidant Capacity [TEAC] and Oxygen Radical Absorbance Capacity [ORAC]).


We noted a decrease in both MDA and H2O2—indicating a lower oxidative stress burden, while also demonstrating an increase in TEAC and NOx. The increase in NOx is important, as blood vessel health and cardiovascular function appears related to circulating concentrations of nitric oxide. NOx is often used as a surrogate marker of nitric oxide production. Although volumes have been written about nitric oxide and its importance within biological systems, the text below provides a brief overview of this gaseous chemical compound.

Nitric oxide (often referred to as NO∙) was initially identified as endothelium-derived relaxing factor, as it was found to result in relaxation of smooth muscle within blood vessels. Nitric oxide is synthesized within the body from the amino acid L-arginine, oxygen, and other cofactors—using a family of enzymes known as nitric oxide synthases. In very high concentrations, nitric oxide favors cell cycle arrest and programmed cell death. However, brief production of nitric oxide at low (nanomolar) concentrations favors beneficial physiological functions, in particular as related to cardiovascular health, which include: decreased platelet and leukocyte adhesion, decreased smooth muscle cell proliferation, and enhanced blood flow and immune defense. In general, a slight elevation in nitric oxide levels is viewed as a positive adaptation to a given intervention (nutritional or otherwise), with potential beneficial effects observed in relation to cardiovascular health. Nitric oxide has received considerable scientific attention over the past few decades since the early work of Furchgott and Zawadzki. In fact, nitric oxide was recognized as the “molecule of the year” by Science magazine in 1992. Additionally, the Nobel Prize in Physiology or Medicine was awarded in 1998 for work related to nitric oxide signaling within the cardiovascular system. Indeed, nitric oxide is of great importance to the scientific community and has clinical significance.


Our data indicate that a 21 day Daniel Fast decreases blood oxidative stress, increases antioxidant capacity, and increases NOx. While additional work is needed to corroborate these findings, these data provide insight into the ability of this Biblically-based fast to significantly improve biomarkers of human health.

Trepanowski JF, Kabir MM, Alleman RJ Jr, Bloomer RJ. A 21-day Daniel fast with or without krill oil supplementation improves anthropometric parameters and the cardiometabolic profile in men and women. Nutr Metab (Lond). 2012 Sep 13;9(1):82.


Fish oil is thought to favorably impact cardiovascular health, with particular emphasis on blood lipids and inflammation. We hypothesized that the addition of krill oil (a type of fish oil) to a Daniel Fast regimen would more favorably impact health outcomes as compared to a placebo. Men and women participated in a 21 day Daniel Fast. Half of the subjects were randomly assigned to consume krill oil daily (2 grams) and half were assigned to receive a placebo (fake supplement). Krill oil is rich in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), two fatty acids known to have health enhancing properties. Krill oil contains phospholipids and is thought to possess enhanced absorption characteristics compared to typical fish oil (which may allow for less krill oil to be consumed relative to typical fish oil). Finally, krill oil contains the antioxidant astaxanthin, which aids in preventing fatty acid oxidation and may serve to protect against free radical damage. Our rationale for the addition of krill oil to this Daniel Fast design was based on our initial findings of a small reduction in HDL-cholesterol (the “good” cholesterol) following a 21 day Daniel Fast, as noted in the article below.

Bloomer RJ, Kabir MM, Canale RE, Trepanowski JF, Marshall KE, Farney TM, Hammond KG. Effect of a 21 day Daniel Fast on metabolic and cardiovascular disease risk factors in men and women. Lipids Health Dis. 2010 Sep 3;9:94.

Because the ideal dietary plan would lead to a reduction in total and LDL-cholesterol (the “bad” cholesterol), as well as a maintenance or elevation in HDL-cholesterol, we decided to add krill oil to this design. Krill oil has been reported in the literature to have favorable effects on lowering total and LDL-cholesterol, and raising HDL-cholesterol.

Resting and fasting blood samples were taken from subjects before and after the 21 day fast. These samples were analyzed for a variety of clinical parameters including serum lipids, complete blood count, comprehensive metabolic panel, insulin, and C-reactive protein (a marker of systemic inflammation). Additional measures of glucoregulatory health (resistin, adiponectin), markers of oxidative stress, and markers of antioxidant capacity were analyzed. A variety of anthropometric variables were also assessed, including weight, circumference measures, and body composition—using dual energy x-ray absorptiometry (DEXA).


Krill oil supplementation had no effect on any outcome measure–results were near identical for the Daniel Fast with krill oil or with placebo. That said, favorable changes were observed in multiple outcomes including reductions in LDL-C, the LDL:HDL ratio fasting blood glucose, fasting blood insulin, the homeostasis model assessment of insulin resistance (HOMA-IR), systolic BP, and body weight.


Following a Daniel Fast dietary plan, with or without krill oil supplementation, improves a variety of cardiometabolic parameters in a wide range of individuals. These results are observed in as little as 21 days.

Bloomer RJ, Trepanowski JF, Kabir MM, Alleman RJ Jr, Dessoulavy ME. Impact of short-term dietary modification on postprandial oxidative stress. Nutr J. 2012 Mar 21;11:16.


In addition to the measurement of resting and fasting data, it is important to assess how individuals respond to stressors. In the case of the present study, the stressor we used was a high-fat meal challenge. We collected blood samples (and measured heart rate and blood pressure) at different times during a four hour post-feeding period (i.e., postprandial assessment). This was done before and after a 21 day Daniel Fast in men and women—in order to have pre and post intervention comparison data for each subject. Our rationale for the inclusion of this meal test was as follows.

We know that simple measurement of bloodborne variables such as glucose and triglycerides in a fasted state (as routinely done in a clinical setting) fails to provide adequate information related to how an individual may metabolize nutrients. Therefore, in much of our work we expose individuals to a “stressor” by using a high calorie, high fat meal. You might think of this in the same way as you would a physical “stress test”, often ordered by a cardiologist to test the function of a patient’s heart. For example, in terms of heart function, patients may present with no abnormalities and appear to be in good physical health when being examined in an office setting while at rest. However, when that same patient walks or runs until exhaustion on a treadmill, abnormalities may indeed be apparent. In this example, the “stressor” was needed to uncover the underlying problem. The same may be true related to the metabolism of certain nutrients—saturated fats in particular, but also simple sugars in those with poor blood glucose control (e.g., diabetics and pre-diabetics). A simple measure of fasting blood glucose and triglycerides does not tell the complete story.

In our lab we prefer to use a milkshake as the test “meal” of choice (as we can precisely measure and weigh each ingredient); our milkshake is made of whole milk, ice cream, and heavy whipping cream. Other labs choose to use whole food meals including biscuits, eggs, cheese, and meat. Regardless of the foods consumed, one thing is clear—ingestion of high fat meals (in particular saturated fat) induces a state of hyper-triglyceridemia (massive elevation in blood fats), which is strongly associated with an increase in free radical production (i.e., reactive oxygen species). This increase in free radical production typically results in an increase in biomarkers of oxidative stress, which has been repeatedly linked to the development and progression of multiple chronic diseases, as well as the aging process. Therefore, minimizing the increase in blood triglycerides (and the subsequent increase in free radical production) following a meal, may have important health implications.

We know from prior research that fasting levels of blood triglycerides are one variable that dictates the triglyceride response to high fat feeding. That is, individuals with elevated fasting triglyceride levels typically have an exaggerated triglyceride response to feeding (as well as an exaggerated oxidative stress response to feeding). The converse is also true. While several excellent articles are available describing the above, the article below reviews the topic briefly, while discussing the difference between high fat and high carbohydrate feedings.

Bloomer RJ, Kabir MM, Marshall KE, Canale RE, Farney TM. Postprandial oxidative stress in response to dextrose and lipid meals of differing size. Lipids Health Dis. 2010 Jul 27;9:79.

Knowing that the Daniel Fast can reduce fasting triglyceride levels and improve antioxidant capacity, it was our hypothesis that the triglyceride and oxidative stress response to feeding would then also be reduced. This may then have major implications in terms of this dietary approach to enhance one’s health.


As expected, values for oxidative stress biomarkers increased in response to the high fat meal both before and after the Daniel Fast intervention. However, the extent of increase was lower after the Daniel Fast for blood triglycerides (11%), malondialdehyde (11%), hydrogen peroxide (8%), and advanced oxidation protein products (12%). There was also a 37% increase noted for NOx.


Following a 21 day Daniel Fast leads to a slight reduction in postprandial oxidative stress. It is possible that a longer time course of adherence to the Daniel Fast regimen may allow for more significant findings.

Alleman RA, Harvey IC, Farney TM, Bloomer RJ. Both a traditional and modified Daniel Fast improve the cardio-metabolic profile in men and women. Lipids Health Dis. 2013, Jul 27:12:114.


We have noted excellent tolerance to the Daniel Fast guidelines in almost all subjects. However, for long-term compliance (beyond the usual 21 day period), modifications in the eating plan are likely needed. One modification is the addition of protein in the form of lean meat and low-fat dairy products. We have noted recently that when individuals extend the Daniel Fast beyond the 21 day period and add 2-3 servings per day of meat or low-fat dairy to the overall plan (while keeping everything else the same), the positive health benefits (in particular as relate to blood lipids) are maintained. This findings, coupled with the fact that the main challenge for many individuals on the fast is the lack of meat and dairy intake, provided us with the idea to do a comparative study of the Daniel Fast with and without meat consumption.

We assigned 29 men and women to either a traditional or modified Daniel Fast for 21 days and measured anthropometric and biochemical markers of health pre and post intervention. The modified Daniel Fast was otherwise identical to the traditional plan but included one serving per day of lean meat and dairy (skim milk), providing approximately 30 grams per day of additional protein.


Compared to baseline, both plans resulted in similar and significant improvements in blood lipids, as well as a reduction in inflammation.


Modification of dietary intake in accordance with either a traditional or modified Daniel Fast may improve risk factors for cardiovascular and metabolic disease. Of course, such a plan would not satisfy the guidelines of the Daniel Fast if being done for strict spiritual purposes. However, this may prove reasonable for those using this approach purely for health related benefits.


If you are an investigator or clinician interested in this line of inquiry, or possibly in collaborating with us on future studies, please contact us for further discussion.