Shaun Ward MSc ANutr
What Is the DASH Diet?
The DASH Diet, also known as the DASH Eating Plan, originated in 1992 and is one of only a few diets that is created by a reputable health organization - National Institute of Health - in an attempt to prevent modern-day dietary issues such as the high intake of saturated fat, omega-6 fatty acids, refined carbohydrates, sodium, and various artificial additives.
DASH is an abbreviated term for the ‘Dietary Approaches to Stop Hypertension’.
The diet has since been endorsed by The National Heart, Lung, and Blood Institute, the US Department of Health and Human Services, The American Heart Association, and the Mayo Clinic.
As the diet is accredited by these health institutes, there has been substantial financial backing for research projects to analyze its effects in different populations.
The nature of DASH is said to be a culmination of the ancient and modern world, utilizing the lessons learned from certain ancient dietary principles whilst specifically targeting the prevention of some of modern societies leading killers.
Unprocessed plant-foods are the focus of the diet, with a heavy emphasis on the consumption of nutrient-dense fruits, vegetables, wholegrains, nuts, dairy (no/low fat), lean meats, and fish.
The Dash Diet Daily Macronutrient Breakdown
You must ensure you stick to the following rules below:
- 25% of your daily calories should be from fat (with <10% from saturated fat).
- 20% of your daily calories should be from protein.
- 55% of your daily calories should be from carbohydrates.
- You must keep your daily cholesterol intake below 150mg.
- You must keep your daily sodium intake below 1,500mg.
- You must ensure you're consuming 4,700mg of potassium.
- You must ensure you're consuming 1,250mg of calcium.
- You must ensure you're consuming 500mg of magnesium.
- You must ensure you're consuming 30g of fiber.
Establishing Your Total Daily Energy Expenditure Is Key
As we explained at the beginning of this article, the program dictates the amounts of each macronutrient (i.e. protein, carbohydrates, fats) you can consume on the daily basis relevant to your total daily caloric intake. Receiving the health benefits of the DASH eating plan assumes you're still not overeating.
Prior to beginning the diet you should work out your approximate total daily energy expenditure, which is just another way of saying that you need to figure out the number of calories your body burns per day (there are calculators online that can help).
Once you've established this, you can properly plan out the proportions as per the macronutrient breakdown (25% of calories from fat, 20% of calories from protein, and 55% of calories from carbohydrates).
What Foods Are You Allowed To Eat?
There is no strict food plan, but daily serving guides for different food groups are given to act as a reference:
- Vegetables (5 servings): Green leafy vegetables such as kale, broccoli, spinach, and collards.
- Fruits (5 servings): Blueberries, bananas, orange, apple.
- Carbohydrates (7 servings per day): Whole grains, oats, quinoa, legumes, and beans.
- Low-fat dairy products (2 servings per day): Skimmed milk, Greek yogurt.
- Lean meat or fish (1 serving a day): Poultry, oily fish.
- Nuts and seeds (3 servings per week): Walnuts, almonds, flax seed, hemp seed
- Other: Olive oil, avocados, soy products.
What Foods Are Not Allowed On The DASH Diet?
No foods are strictly off limits, however we've listed a few things you'll likely want to avoid to ensure you do not exceed the macronutrient requirements of the diet plan:
- Foods that are high in sodium (Deli meats, soup, condiments (such as ketchup, BBQ sauce), bacon, sausages).
- Any food that's been fried.
- Processed meats.
- Fast food.
What Are Some Meal Examples?
You won't really have to drastically change up the foods you eat on a daily basis - you simply need to make sure you stick to the macronutrient rules (which in most cases will just mean dropping some "bad foods" and/or cutting back on the overall volume of food you're consuming).
Below we've listed some meal examples to make planning out the diet easier.
- Oatmeal with skimmed milk, blueberries and fresh orange juice.
- Whole-wheat toast with jam, fresh orange juice and an apple.
- Natural yogurt with strawberries and mixed seeds.
- Tuna and mayonnaise sandwich with green salad.
- Kale, black bean and avocado burrito bowl.
- Falafel, roasted vegetables and couscous.
- Salmon, boiled potatoes and vegetables.
- Chickpea and lentil curry with spinach.
- Sweet potato and black bean veggie burgers.
- Canned peaches and low-fat yogurt.
- Banana, flaxseed and kale smoothie.
- Wholegrain crackers with low-fat cheese.
It The DASH Diet Useful For Weight Loss?
It potentially can help you shed some weight, but we wouldn't necessarily recommend following the DASH eating plan for the sole purposes of burning body.
In its standard form, the DASH Eating Plan isn't a caloric deficit diet. As mentioned above, the diet is for those with high blood pressure; if you're looking to lose weight, there are simply more effective diets that are designed especially for losing weight.
Despite this, as the diet advocates switching food options from processed calorie-dense sources to unprocessed lower calorie sources, weight loss is sometimes an outcome as overall calorie intake will decrease in most circumstances, though this is entirely dependent on an individual basis.
Followers will also experience reduced rates of hunger from the high intake of dietary fiber on the diet, which has frequently been linked to greater meal satiety.
Typical weight loss seen on it are:
However, some studies have only reported significant amounts of weight loss when they have programmed the diet specifically for weight loss (calorie deficit) .
- 7kg loss in 16 weeks on a DASH weight loss diet.
- 3kg loss in 16 weeks on a DASH only diet.
The Potential Benefits of the DASH Diet
Below we've listed every potential benefit we've found with credible scientific backing:
It May Reduce Blood Pressure
The DASH diet has been ranked the best overall diet for managing blood pressure by the ‘U.S. News & World Report’.
Scientific reviews have also concluded that it significantly reduces systolic and diastolic blood pressure, total cholesterol, and LDL-cholesterol concentrations (“bad” cholesterol) .
This is likely a key reason why DASH diets, or those all similar in nutrient composition, reduce the incidence of cardiovascular diseases and stroke by ~20% .
Importantly, even in controlled feeding studies where body weight is purposefully maintained, significant reductions in systolic and diastolic blood pressure are recorded in healthy individuals .
This cannot be said for most diets, where health benefits such as reduced blood pressure are simply a secondary outcome that stem from weight loss.
As expected, individuals with medically defined high blood pressure report greater improvements in blood pressure on the DASH diet compared to healthy individuals.
Based on the scientific literature, it is reasonable to expect a ~5-10mmHg decrease in systolic blood pressure from the DASH diet alone . Even larger changes can be made when the diet is combined with exercise and a structured weight loss eating plan.
A big factor in lowering blood pressure on the diet is the restriction of sodium intake. In fact, the greatest reductions in blood pressure on the DASH diet are in those with the lowest salt consumption .
Sodium intake has a negative effect on blood pressure by modifying electrolyte balances in the blood, which can cause fluid retention and increase strain on blood vessels.
Various other characteristics of the DASH diet such as increased fiber, potassium, calcium, and magnesium intakes have also been associated with reduced blood pressure due to their ability to increase sodium excretion by the kidneys .
Aside from factors relating to sodium, the high intake of inorganic nitrate and its effect on increasing the generation of nitric oxide may also be relevant to reducing blood pressure . This is due to nitric oxide causing blood vessels to relax, dilate, and expand.
It is estimated that a standard DASH dietary plan results in a nitrate intake of ~1200mg per day, which is up to 10 greater than that of a typical western diet.
It May Help Decrease The Risk Of Diabetes
The DASH diet is inversely associated with the incidence of type 2 diabetes .
A ~20% decreased risk of developing type 2 diabetes on the DASH diet has also been found in scientific reviews .
These results are not surprising considering even generic dietary recommendations such as ‘eat more vegetables, and reduce sugar and alcohol intake’ have shown to reduce the incidence of type 2 diabetes by up to ~30% .
The main mechanism by which the DASH diet reduces diabetes risk is by lowering insulin resistance - the diminished ability of cells to respond to insulin and transport glucose from the blood to other tissues . The adaptations in insulin resistance become more profound as the food quality on the diet improves and becomes more aligned with the exact dietary recommendations.
Similarly, studies utilizing glucose tolerance tests find that 6 months on the DASH diet significantly improves insulin sensitivity - how sensitive the body is to the effects of insulin .
Clearly, the improvements in insulin sensitivity can reduce the risk of diabetes by greatly improving glycemic control and avoiding dramatic fluctuations in blood sugar levels.
A key issue to note is that individuals previously diagnosed with type 2 diabetes may have issues with the high carbohydrate intake on the diet – 55% of total calories. This is despite findings that indicating that there are improvements for blood glucose control on the DASH diet in diabetics . The effect of the diet in diabetics likely varies depending on the individual, and a doctor should be consulted before use in this population.
It May Help Prevent Cancer
Although there has been no direct analysis of the DASH diet on cancer, adherence to individual components of the diet – high fiber, vitamins, and antioxidants, with low saturated fat and carcinogens - has been significantly related to lower rates of various cancers .
The DASH diet mainly prevents cancer by improving the composition of mucus that lines the gastrointestinal tract, which acts as a protective barrier of the gut . However, this mechanism has currently been reported only in animal studies, and human research is needed.
The large consumptions of wholegrains on the DASH diet are suggested to guard against cancer as they contain many anti-cancer components such as dietary fibers, micronutrients, antioxidants, phenolic acids, lignans, and phytoestrogens.
Dietary fiber is particularly crucial for preventing against colorectal cancer because it reduces fecal carcinogens and decreases the contact time between carcinogens and colorectal cells.
The DASH diet also limits the intake of meat, specifically red and processed meat, that is known to contain substances such as N-Nitroso compounds, heterocyclic amines, and heme iron, which can produce mutagens and carcinogens that upregulate cancer formation.
The high fruit and vegetable intake on the diet also contains cancer-fighting compounds such as beta-carotene, fiber, vitamins, alpha-tocopherol, retinoids, phytoestrogens, and folate. These protect against cancer through potent mechanisms such as hindering cancer cell growth, normalizing DNA synthesis, and defending against cellular and DNA damage.
Specifically, sulforaphane, found in cruciferous vegetables, is an important organosulfur component that has recently been to have a pronounced effect on cancer protection in epidemiological studies .
Possibly One of The Most Sustainable Diets
A great aspect of the DASH diet, if not the best, is that it does not make extreme dietary changes that usually cause individuals to return to normal eating habits.
After all, in the long-term, a diet is only as good as it is sustainable.
Individuals are not told to completely remove the intake of a specific nutrient or food group, but instead focus on making slight dietary adjustments to emphasize the consumption of unprocessed plant-based foods over harmful foods such as processed meats and refined carbohydrates.
This means the positive health outcomes will not be seen for only one, two, or three months, but for a lifetime (ideally!).
The DASH diet is one of few diets created by a major health organization in an attempt to prevent modern-day dietary issues, with a specific initial aim to reduce blood pressure.
The focus is placed on unprocessed plant-foods, with a heavy emphasis on the consumption of fruits, vegetables, wholegrains, nuts and legumes. Low-fat dairy and fish are included in the diet, but meat intake is limited to only 1 serving a day.
There is convincing evidence that the diet can significantly reduce blood pressure and insulin resistance, which has great influence on preventing cardiovascular diseases and type 2 diabetes. Components of the diet may also be helpful for protecting against cancer, although more research is needed in this area.
While the studies do show it can help you lose weight, it's probably not a great diet for that specific purpose as it doesn't really focus on caloric deprivation.
Overall, The DASH diet is a very healthy and sustainable eating plan that can be implemented by the vast majority of individuals to tackle most issues that stem from malnutrition.