Calorie for calorie, meat causes increased weight gain.
The EPIC-PANACEA study was conducted between 1992 and 2000 in 10 European countries that had almost 300,000 participants--one of the largest of its kind. One surprising result is the finding that when comparing those who ate meat compared to those who didn’t, the meat eaters gained weight, even after controlling for caloric intake, exercise, and other lifestyle factors! When studied over a 5 year period, the meat eaters gained almost 6 lbs more than the non-meat eaters. What kind of meat had the strongest association? Chicken.
Conclusions of the Meat Consumption analysis: “Our results suggest that a decrease in meat consumption may improve weight management”
Source:
“Meat Consumption and Prospective Weight Change in Participants of the EPIC-PANACEA study” (https://www.ncbi.nlm.nih.gov/pubmed/20592131)
Is there such a thing as negative net calorie food?
Is there a food that has fewer calories than the act of consuming it? Yes and no. No food in isolation (even celery) can do this (you will net +2 calories with celery). However, if you eat the right foods before a meal, you can achieve this overall. Researchers at Penn State wanted to study how pre-loading a meal with a low calorie dense food would affect the overall calories consumed. Study participants were given a pasta meal and allowed to eat as much as they wanted to establish a baseline. The average calories consumed was about 800 (kcal).
Later the same participants were brought back and given the same opportunity, but before they could dive into the pasta, they were made to consume an entire small salad (150 grams, 50 calorie salad). This time, the participants, on average, ate 65 fewer calories of pasta. The study was repeated with a larger salad, and the effect was the same. The presence of the salad before the meal more than made up for the calorie content of the salad. Eating a higher volume of food resulted in fewer calories consumed.
The study concluded: “ ‘Eat less’ is not always the best advice. For foods very low in energy density, such as water-rich vegetables, larger portions increase satiety and reduce meal energy intake.”
Source:
“Salad and Satiety: Energy Density and Portion Size of a First-Course Salad Affect Energy Intake at Lunch” (https://www.ncbi.nlm.nih.gov/pubmed/15389416)
Eat More, Weigh Less, and While Consuming More Nutrients
One common concern about meat-free diets is that they are lacking in essential nutrients (dairy and meat associations love to push this line). In 2011, a study was published that directly addressed this concern. 13,000 people participated in this study that simply compared the nutrients obtained in a meat vs meat-free diet.
The study found that the vegetarians were getting higher amounts of almost every nutrient: fiber, vitamins A, C, E, thiamin, riboflavin, folate, calcium, magnesium, iron, and potassium to name a few. The vegetarians were found to be lacking in a few areas: total fat, saturated fat, and cholesterol. Well, what about protein? The study also found “the adjusted mean intake of protein by vegetarians was not lower than the recommended amounts for adults.”
In terms of weight management, the study found that vegetarians consumed 363 fewer calories (kcal) than they meat eaters. Additionally, the vegetarians, on average, had a BMI of 1.4 lower than the meat eaters. Essentially, the study found that even though vegetarians were eating to satiety, they were eating the equivalent calories of what an omnivore eats during a calorie restricted diet.
Since most diets can result in short term weight loss, long term compliance is almost always the downfall. So, how sustainable are vegetarian diets? A analysis was published in 2010 that compared the adherence and acceptability of four different diets: 1. Low calories 2. Low fat omnivorous, 3. Vegetarian and Vegan, and 4. Low carbohydrate. This analysis concludes, in part, “Only vegetarian, vegan, and low-fat diets have been studied for one year or longer, and each type has had demonstrable sustainability over the longer term.” Specifically addressing the vegan diet, the analysis says, “... individuals prescribed vegan diets in research studies have reported improved quality of life, weight loss, and increased energy.”
Sources
“A vegetarian dietary pattern as a nutrient-dense approach to weight management: an analysis of the national health and nutrition examination survey 1999-2004” (https://www.ncbi.nlm.nih.gov/pubmed/21616194)
“Four therapeutic diets: adherence and acceptability”
(https://www.ncbi.nlm.nih.gov/pubmed/21144137)
Conclusion:
By eating a whole food plant based diet, the focus of weight loss shifts from quantity (restriction) to quality (high nutrient density). Even those with the most ironclad will, cannot, over time, force themselves to lose weight by food restriction. If you want a realistic, long term strategy to achieving a healthy weight while at the same time reducing your risk of heart disease, many forms of cancer, hypertension, and diabetes, there is no other option than eating whole plant foods.