Weight loss diets create deficiencies

In October 2017 the CDC reported that more than 1 in 3 Americans are obese (39.8%).1 Those who are overweight or obese are more likely to suffer from heart disease, stroke and diabetes, among other things.2,3

Even a 5-10% decrease in weight for overweight and obese individuals has been shown to reduce risk factors for obesity-associated chronic diseases.4,5

It is important to not only lose weight, but to lose weight healthfully. If you reduce your calorie intake, understand you'll have deficiencies in your diet that you'll need to compensate for.


Three popular diets lack these micronutrients

Many weight loss diets focus on restricting certain macronutrients like carbs or fat, but they overlook micronutrients like vitamins and minerals. In the early 2000s, researchers decided to analyze the micronutrients in three popular low-calorie diets based on their protein, fat and carb content.6


Low-carb diet

The researchers discovered that the high-fat, low-carb, high protein diet (e.g. Dr. Atkins' New Diet Revolution; Protein Power; Life Without Bread) was deficient in vitamins A, E, B6, B1 (thiamin), folate, calcium, magnesium, iron, potassium and dietary fiber.


Balanced diet

The moderate fat, balanced nutrient reduction diet (e.g. USDA Food Guide Pyramid; DASH diet; Weight Watchers) can be low in B12, calcium, zinc, magnesium, iron and dietary fiber if the proper food choices are not made.


Low-fat diet

Low fat or very low-fat diets (e.g. Dr. Dean Ornish's Program for Reversing Heart Disease: Eat More, Weigh Less; The New Pritikin Program) are low in vitamins E, B12 and zinc.


...Vegan, paleo & keto aren’t much better

In January 2018, different researchers published information on new, more relevant, popular diets.7 Like previous studies, they found that popular calorie-restricted diets were lacking in multiple micronutrients. Each diet was also examined after it was adjusted up to 2,000 calories, simulating an eating plan not specifically designed for weight loss. Even without calorie restriction, all of the eating plans were deficient in vitamin D and another micronutrient.

The researchers presented the different micronutrient intakes as a percent of the Dietary Reference Intake (DRI). A DRI of 100% is the average daily level of intake sufficient to meet the nutrient requirements of nearly all (97-98%) healthy people. For each diet, we have included a chart (on the right side of this page) showing the micronutrients below 90% of the DRI.


What vegan, keto, paleo, low carb and others are lacking


Vegan diet

Researchers calculated the weight-loss version of this diet to be an average of 1,302 calories per day. It is lacking seven important micronutrients, with only 6% of the recommended amount of vitamin D. Low vitamin D levels are associated with serious and chronic health conditions. Optimal levels allow the immune system, nervous system, heart, joints and more to function properly.

The Vegan diet is also deficient in vitamin B12, which is essential for proper energy metabolism, nerve and mental function, red blood cell formation and cardiovascular health. This diet has shortages of the key minerals calcium, selenium and zinc, which are involved in the health of bones and the immune system. Even during calorie balance, the Vegan diet is lacking vitamins B12 and D.


Low-Carb, High-Animal Protein diet

Even though they have their differences, both paleo and keto diets appear to fall under the umbrella of this broad weight-loss plan. It especially lacks calcium and vitamin D. Calcium is best known for supporting bone health but is also required for proper nerve and muscle function as an electrolyte. This diet is also deficient in magnesium and potassium, two other key electrolytes important for nerve and muscle function.


Healthy Eating Pyramid diet

This diet, developed by Harvard Medical School, was meant to improve on the USDA Food Guide Pyramid.8 It is not a weight loss diet, so only a 2,000 calorie version is shown. Like the other diets, it is very deficient in vitamin D. Plus, it lacks adequate calcium.


Is reaching 100% of the RDI realistic?

Looking back at another similar study done in 2010, the researchers observed that to get 100% of the RDI for 21 essential micronutrients, you would need to consume between 2,425 and 5,000 calories depending on which diet you followed. Your calorie intake would increase even higher if you were looking to meet the RDI for 27 essential micronutrients.9

Based on this information, it may be even more important to take a multi-vitamin and mineral formula during a weight loss plan. Even when not dieting, the American Medical Association advises that all adults take at least one multivitamin pill a day.10 The Dietary Guidelines Advisory Committee also recommends the use of dietary supplements to help fill nutrient gaps in the American diet.11


The road to better health

If you are on a weight loss diet, keep up the hard work! You are on the road to better health. However, understand that you may be missing out on key vitamins and minerals whether you are dieting or not. Consider adding a multi-vitamin and mineral formula to your daily regimen as an insurance policy. Taking a few supplements in addition to a good diet can help you enjoy vibrant health.


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