Losing vitamins – along with weight – on a diet
Losing vitamins – along with weight – on a diet
If you’re looking to shed a few pounds, you’re probably focused on the amounts of fats, carbs or protein you can eat under the various diet plans available. But a new Stanford study suggests that you should also pay attention to how a diet will affect your consumption of key vitamins and minerals.
The study involving four popular diets – Atkins, Zone, Ornish and the LEARN diet based on the U.S. Department of Agriculture’s food pyramid – showed that only those assigned to follow the Zone diet were able to avoid increasing their risks for inadequate intake of essential vitamins and minerals.
Christopher Gardner, PhD, associate professor of medicine at the Stanford Prevention Research Center and the lead author of the study, urged people to consider the overall nutritional quality of any diet plan they select, rather than focusing solely on the “macronutrients” such as carbohydrates and fats.
The study, which will be published in the August issue of the American Journal of Clinical Nutrition, is a follow-up to a 2007 paper in which Gardner and his colleagues did a head-to-head comparison of the four diet plans.
In the new study, Gardner looked at the vitamin and mineral levels of participants at the time they enrolled in the study and compared them to the levels eight weeks into their diets – when the women were the best at sticking to the new food plans. They found that in three of the diet groups, significant portions of the women increased their risk for inadequate intake of several micronutrients, such as vitamin C, vitamin E, thiamine, folic acid, iron, calcium and zinc.
That wasn’t the case for the women assigned to the Zone diet, who actually increased their intake of some nutrients. Gardner noted that the Zone plan is a “moderately low-carbohydrate” diet, and speculated that this approach to reducing carbs may help dieters maintain a healthier balance. “You can cut a lot of calories out of your diet by eliminating refined grains and added sugars – the least nutritious carbs – without sacrificing nutrient adequacy,” Gardner said.
* Photo by Steve Fisch
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Christopher Gardner, PhD. Bio.
Christopher Gardner
Academic Appointments
Associate Professor (Research), Medicine – Stanford Prevention Research
Member, Cancer Center
> Positions
1997-1999 Research Associate, Department of Medicine, Stanford University
1999-2001 Assistant Professor, Dept of Epidemiology and Prevention, UC Davis
2001-2007 Assistant Professor, Department of Medicine, Stanford University
2007-present Associate Professor, Department of Medicine, Stanford University
> Administrative Appointments
Education Committee, The Obesity Society (2009 – 2011)
Nutrition Committee, American Heart Association (2009 – 2011)
> Honors/Awards/Fellowships
1988 University of California Regents Fellowship
1989 Outstanding Teaching Assistant, Department of Nutritional Sciences
1994 AHA Fellow, 20th U.S. 10-day Seminar on Epidemiology & Prevention of CVD
1995-1997 American Heart Association Postdoctoral Training Grant Recipient
2003 Distinguished Honorary Award, San Jose State University Department of Nutrition
2005 Outstanding Teacher, SPRC, Department of Medicine
> Education/ Training
Colgate University, Hamilton, NY B.A. 1977-1981 Philosophy
University of California, Berkeley Ph.D. 1989-1993 Nutrition Science
Stanford University, California Post. Doc. 1993-1997 CVD Epidemiology
> Current Research Interests
The role of nutrition and preventive medicine, with particular interests in: plant-based diets and phytochemicals; cardiovascular disease and cancer prevention; weight loss diets; clinical trials and epidemiology.
> Clinical Trials
Effects of Glutathione (an antioxidant) and N-Acetylcysteine on Inflammation
Adding Sleep Intervention to Traditional Diet and Exercise Approach to Weight Loss
Effect of Fish Oil on Plasma Triglycerides in Adults
Effects of Dietary Antioxidants on Cardiovascular Risk Factors
Effects of Omega-3 Fatty Acids on Markers of Inflammation
Effects of Raw vs. Other Milk Sources on Lactose Digestion
** The above story is adapted from materials provided by Stanford University School of Medicine
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