If you are trying to lose weight by following a not-too-strict diet, a bowl of salty snacks can undermine your success. Pistachio nuts are a better choice, according to an article that researchers at the UCLA Center for Human Nutrition published in the Journal of the American College of Nutrition.
Most scientists will tell you that you lose weight by consuming fewer calories than you burn, and that’s the end of the story. But a growing minority say that the type of calories consumed is also important. Their motto is “A calorie is not a calorie”. The more serious popular weight loss diets are partly based on this principle.
In the new appriach the wrong kind of calories tend to come from quickly absorbed carbohydrates. Epidemiologists notice that people who consume carbohydrates in the form of crisps, potato products and soft drinks put on weight more easily than the clever people who manage to eliminate these foods from their diet.
Salty snacks like pretzels also contain these extra-fattening carbohydrates. The nutritional values are reproduced below on the right.
The researchers wanted to know what the best kind of snack is for dieters: food containing healthy fats or food with a high carbohydrate content. Studies show that a diet containing lots of healthy fats in the form of olive oil or nuts is healthy, but because ‘fat’ has a bad name, many dieters avoid all foods that contain fat. The researchers’ intention was to find out whether this is a correct assumption.
The researchers put two dozen test subjects on a diet that provided 500 kcals fewer per day than they burned for a period of 12 weeks. Every evening the subjects ate 220 kcal in the form of 56 g salted pretzels. An equal-sized group of subjects followed an identical diet, but ate 240 kcal in the form of 53 g pistachio nuts every evening. The nutritional values are shown above on the left.
The researchers discovered that the cardiovascular health improved in the pistachio group. The concentration of triglycerides [in other words fat] in their blood went down, as you can see in the figure below. Click here for the full table.
The figure above shows how the subjects’ BMI changed throughout the 12 weeks that the experiment lasted. In the pretzel group the average BMI dropped from 30.9 to 30.3; in the pistachio group the drop was from 30.1 to 28.8.
In terms of kilograms this means: the pistachio group went from 86.0 to 82.3 kg, losing 3.7 kg; the pretzel group went from 85.5 to 92.8 and lost 2.7 kg. So the pistachio group lost a kilogram more than the pretzel group.
Pistachio nuts reduce triglycerides and body weight by comparison to refined carbohydrate snack in obese subjects on a 12-week weight loss program.
Li Z, Song R, Nguyen C, Zerlin A, Karp H, Naowamondhol K, Thames G, Gao K, Li L, Tseng CH, Henning SM, Heber D.
Center for Human Nutrition, Warren Hall, Room 12-217, 900 Veteran Ave, Los Angeles, CA 90095, USA. firstname.lastname@example.org
There is a widely held view that, due to high fat content, snacking on nuts will lead to weight gain, ultimately causing unhealthy changes in lipid profiles. This study is designed to study the effects of pistachio snack consumption on body weight and lipid levels in obese participants under real-world conditions.
Participants were randomly assigned to consume 1 of 2 isocaloric weight reduction diets for 12 weeks, with each providing 500 cal per day less than resting metabolic rate. Each diet included an afternoon snack of either 53 g (240 cal) of salted pistachios (n ?=? 31) or 56 g of salted pretzels (220 cal; n ?=? 28).
Both groups lost weight during the 12-week study (time trend, p < 0.001), but there were significant differences in the changes in body mass index between the pretzel and pistachio groups (pistachio, 30.1 ± 0.4 to 28.8 ± 0.4 vs. pretzel, 30.9 ± 0.4 to 30.3 ± 0.5). At 6 and 12 weeks, triglycerides were significantly lower in the pistachio group compared with the pretzel group (88.04 ± 9.80 mg/dL vs. 144.56 ± 18.86 mg/dL, p ?=? 0.01 at 6 weeks and 88.10 ± 6.78 mg/dL vs. 132.15 ± 16.76 mg/dL, p ?=? 0.02 at 12 weeks), and there was a time trend difference between the 2 groups over the 12 weeks (p < 0.01). There were no significant differences in total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, insulin, or glucose between the 2 groups.
Pistachios can be consumed as a portion-controlled snack for individuals restricting calories to lose weight without concern that pistachios will cause weight gain. By comparison to refined carbohydrate snacks such as pretzels, pistachios may have beneficial effects on triglycerides as well.
PMID: 20833992 [PubMed – indexed for MEDLINE]