Reflecting On The 5:2 Diet & Intermittent Fasting
Posted: Mon May 13, 2013 12:15 pm
Some comments on the 5:2 diet, Intermittent Fasting (IF), Calorie Restriction (CR) and Optimal Nutrition (ON)
First, as explained in the "Eating Between Meals' thread, the single most important thing anyone can do in regard to their diet and health is to understand and apply the basic principles and guidelines.
http://www.drmcdougall.com/forums/viewt ... 22&t=26337
"Bottom line, following the recommendations here to consume a unrefined unprocessed plant based diet that is low in calorie density, high in nutrient density and high in satiety, along with the proper amount and type of physical activity may be the most important issue. Whether someone does this in 3 meals vs 5 meals vs 1 meal, may be less important than total calories and overall food choices, and a fine detail that would be up to the individual based on which method helps them incorporate the more important principles."
"Some people just can't maintain a meal plan with fewer meals and some just can't maintain a meal plan with more frequent meals. I am one of the latter, and so, I keep a more limited meal plan but would not insist on that for someone who felt more comfortable with more frequent meals as long as the overall dietary and nutritional pattern is the same."
Basing your overall diet on calorie density is a much better approach to incorporating the recommended guidelines and principles as it addresses many important issues at once...
First, it allows you to eat whenever hungry until you are comfortably full, which addresses the key issues of hunger and satiety.
Second, the recommended foods are not only low in calorie density and high in satiety, they are also the foods that are the most nutrient dense, which addresses the issue of optimal nutrition
While some people are able to do fine with occasional fasting and the skipping of meals, whether or not this is feasible for someone should not be their first and/or main priority.
In addition, we live in a toxic food environment and trying to incorporate meal skipping and intermittent fasting may prove not only difficult to many, but also detrimental. Two recent studies highlight some of these issues...
1) Caloric deprivation increases responsivity of attention and reward brain regions to intake, anticipated intake, and images of palatable foods. NeuroImage, Volume 67, 15 February 2013, Pages 322–330
http://www.sciencedirect.com/science/ar ... 1912011408
(An article on the study)
"Results imply that dieting characterized by meal skipping & fasting would be less successful than weight loss efforts characterized by intake of low energy dense healthy foods."
"The implications of this imaging study are crystal clear; if people want to lose excess weight, it would be more effective to consume healthy, low-fat/low-sugar foods during regular meals, rather than go for long periods of time without any caloric intake"
http://www.eurekalert.org/pub_releases/ ... 050213.php
2) Wansink B, Tal A "Fattening fasting: hungry grocery shoppers buy more calories, not more food" JAMA Intern Med 2013; DOI: 10.1001/jamainternmed.2013.650.
http://archinte.jamanetwork.com/article ... id=1685889
(An article on the study)
Short-term food deprivation (fasting, skipping meals) increases overall grocery shopping & leads shoppers to buy 31% more high-calorie foods.
http://www.news.cornell.edu/stories/201 ... -fattening
My concerns...
- Many people who come from the old dieting/restriction mentality still apply that thinking to this way of eating and still restrict portions & food volume, not understanding that due to the low calorie density of this food, you actually do not need to do that and often need to eat more volume. So, they restrict the consumption of the healthy recommended foods, that are low in calorie density, then end up starving and eventually binging on unhealthy regular foods or vegan/plant based junk foods.
- In an attempt to maximize the impact of this way of eating, people often shift the calorie density of their diet too low, focusing mostly on very low calorie dense foods like mostly veggies, skip healthy foods like whole grains, roots/tubers and even legumes. In doing so, they may get lots of food volume but they do not get enough calories and eventually get very hungry and also end up starving and end up binging on high fat, high sugar raw vegan things like dried fruit, nuts and date/nut treats or just vegan/plant based junk food.
- In addition, even when switching to this way of eating, people may skip meals during the day &/or make their meals very small thinking by doing this and then eating a sensible healthy dinner, they will be helping to reduce overall caloric intake. While this may often prove easy during the day when people are busy and hunger is still somewhat manageable, it usually fails in the evening when they are home and hunger has become unmanageable. So instead of a sensible healthy dinner, they eat everything not nailed down! Then, the next morning they repent and try again by skipping breakfast and/or lunch and/or making them very small and end up just repeating an unhealthy pattern, over and over.
- While these scenarios can happen to anyone trying to follow a whole food, plant based diet depending on how they interpret & apply the principles, from my personal & professional experience, it seems to be more common in the raw vegans, who end up overdoing the high fat/high sugar foods/treats (from nuts, dried fruits, juices etc), those who overly restrict any of the programs (thru portion control &/or CR), and in those who overly limit or eliminate the intact whole grains, starchy vegetables, roots & tubers (& sometimes even beans).
- Of course, we will always find the few people who are able to do IF and CR with portion control and food restriction and in whom, satiety and hunger are just not issues. However, 70% of Americans struggle with weight issues and have proven that they can not control their food intake in this toxic ad libitum food environment. And, the odds are that those who come to me for help (or these forums), this percentage is much higher. Otherwise, they would not be here.
So..
1) If one is trying to lose weight, there are only 3 studies I know of to date in the literature that directly compare the effects of IF vs CR, there is one review comparing the results from separate studies of IF and CR and these studies do not show any advantage to IF (see below). In addition, as noted above, there are several studies that show meal skipping and fasting may not work for many people.
2) If one is trying to lower IGF-1, there is no known benefit to IF over CR in this regard. Focusing on IGF-1 is missing the point. IGF-1 should be the result of our efforts and not the focus. In addition, if the reason for lowering IGF-1 is to impact cancer, then lowering IGF-1, which is only a marker, is not the same as lowering cancer risk or incidence. However, a total lifestyle program that included regular exercise and a low fat, near vegetarian diet (without IF), did lower IGF-1 levels and impact cancer cell growth and the progression of some types of cancer (breast, prostate). This does not mean it will impact cancer cell growth and the progression of all and any cancer.
http://www.ncbi.nlm.nih.gov/pubmed/12588089
http://www.ncbi.nlm.nih.gov/pubmed/16094059
It is proposed that one of the benefits of this way of life that lowers the IGF-1 is both the reduced protein intake and the amino acid profile of the protein on this program.
http://cebp.aacrjournals.org/content/11 ... 1.abstract
3) If one was interested, the best way to incorporate the potential benefits of CR & ON that also addresses the issues of satiety and hunger, is through the understanding and application of the principles of calorie density and the MWL program.
4) If one is on a CR'd version of this program and is trying to fine tune it to see if there is some potential additional benefits to incorporating IF as part of their CR'd program, then that is fine, but first, they really need to understand and implement the basics of calorie density/MWL into their lives first.
Which bring us right back to my original point....
"Bottom line, following the recommendations here to consume a unrefined unprocessed plant based diet that is low in calorie density, high in nutrient density and high in satiety, along with the proper amount and type of physical activity may be the most important issue. Whether someone does this in 3 meals vs 5 meals vs 1 meal, may be less important than total calories and overall food choices, and a fine detail that would be up to the individual based on which method helps them incorporate the more important principles."
In Health
Jeff
In all studies the outcome was the same: No significant differences in weight loss, or changes in body composition.
1) Am J Clin Nutr. 1989 Aug;50(2):248-54. Evaluation of an alternating-calorie diet with and without exercise in the treatment of obesity.
http://www.ncbi.nlm.nih.gov/pubmed/2667313
2) Int J Obes (Lond). 2011 May;35(5):714-27. doi: 10.1038/ijo.2010.171. Epub 2010 Oct 5. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women.
http://www.ncbi.nlm.nih.gov/pubmed/20921964
3) Intermittent versus daily calorie restriction: which diet regimen is more effective for weight loss? Varady KA. Obes Rev. 2011. Jul;12(7):e593-601. doi: 10.1111/j.1467-789X.2011.00873.x. Epub 2011 Mar 17. Review. PMID: 21410865
http://www.ncbi.nlm.nih.gov/pubmed/?term=21410865
4) Menopause. 2012 Aug;19(8):870-6.
Short- and long-term effects of continuous versus intermittent restrictive diet approaches on body composition and the metabolic profile in overweight and obese postmenopausal women: a pilot study.
http://www.ncbi.nlm.nih.gov/pubmed/?term=22735163
First, as explained in the "Eating Between Meals' thread, the single most important thing anyone can do in regard to their diet and health is to understand and apply the basic principles and guidelines.
http://www.drmcdougall.com/forums/viewt ... 22&t=26337
"Bottom line, following the recommendations here to consume a unrefined unprocessed plant based diet that is low in calorie density, high in nutrient density and high in satiety, along with the proper amount and type of physical activity may be the most important issue. Whether someone does this in 3 meals vs 5 meals vs 1 meal, may be less important than total calories and overall food choices, and a fine detail that would be up to the individual based on which method helps them incorporate the more important principles."
"Some people just can't maintain a meal plan with fewer meals and some just can't maintain a meal plan with more frequent meals. I am one of the latter, and so, I keep a more limited meal plan but would not insist on that for someone who felt more comfortable with more frequent meals as long as the overall dietary and nutritional pattern is the same."
Basing your overall diet on calorie density is a much better approach to incorporating the recommended guidelines and principles as it addresses many important issues at once...
First, it allows you to eat whenever hungry until you are comfortably full, which addresses the key issues of hunger and satiety.
Second, the recommended foods are not only low in calorie density and high in satiety, they are also the foods that are the most nutrient dense, which addresses the issue of optimal nutrition
While some people are able to do fine with occasional fasting and the skipping of meals, whether or not this is feasible for someone should not be their first and/or main priority.
In addition, we live in a toxic food environment and trying to incorporate meal skipping and intermittent fasting may prove not only difficult to many, but also detrimental. Two recent studies highlight some of these issues...
1) Caloric deprivation increases responsivity of attention and reward brain regions to intake, anticipated intake, and images of palatable foods. NeuroImage, Volume 67, 15 February 2013, Pages 322–330
http://www.sciencedirect.com/science/ar ... 1912011408
(An article on the study)
"Results imply that dieting characterized by meal skipping & fasting would be less successful than weight loss efforts characterized by intake of low energy dense healthy foods."
"The implications of this imaging study are crystal clear; if people want to lose excess weight, it would be more effective to consume healthy, low-fat/low-sugar foods during regular meals, rather than go for long periods of time without any caloric intake"
http://www.eurekalert.org/pub_releases/ ... 050213.php
2) Wansink B, Tal A "Fattening fasting: hungry grocery shoppers buy more calories, not more food" JAMA Intern Med 2013; DOI: 10.1001/jamainternmed.2013.650.
http://archinte.jamanetwork.com/article ... id=1685889
(An article on the study)
Short-term food deprivation (fasting, skipping meals) increases overall grocery shopping & leads shoppers to buy 31% more high-calorie foods.
http://www.news.cornell.edu/stories/201 ... -fattening
My concerns...
- Many people who come from the old dieting/restriction mentality still apply that thinking to this way of eating and still restrict portions & food volume, not understanding that due to the low calorie density of this food, you actually do not need to do that and often need to eat more volume. So, they restrict the consumption of the healthy recommended foods, that are low in calorie density, then end up starving and eventually binging on unhealthy regular foods or vegan/plant based junk foods.
- In an attempt to maximize the impact of this way of eating, people often shift the calorie density of their diet too low, focusing mostly on very low calorie dense foods like mostly veggies, skip healthy foods like whole grains, roots/tubers and even legumes. In doing so, they may get lots of food volume but they do not get enough calories and eventually get very hungry and also end up starving and end up binging on high fat, high sugar raw vegan things like dried fruit, nuts and date/nut treats or just vegan/plant based junk food.
- In addition, even when switching to this way of eating, people may skip meals during the day &/or make their meals very small thinking by doing this and then eating a sensible healthy dinner, they will be helping to reduce overall caloric intake. While this may often prove easy during the day when people are busy and hunger is still somewhat manageable, it usually fails in the evening when they are home and hunger has become unmanageable. So instead of a sensible healthy dinner, they eat everything not nailed down! Then, the next morning they repent and try again by skipping breakfast and/or lunch and/or making them very small and end up just repeating an unhealthy pattern, over and over.
- While these scenarios can happen to anyone trying to follow a whole food, plant based diet depending on how they interpret & apply the principles, from my personal & professional experience, it seems to be more common in the raw vegans, who end up overdoing the high fat/high sugar foods/treats (from nuts, dried fruits, juices etc), those who overly restrict any of the programs (thru portion control &/or CR), and in those who overly limit or eliminate the intact whole grains, starchy vegetables, roots & tubers (& sometimes even beans).
- Of course, we will always find the few people who are able to do IF and CR with portion control and food restriction and in whom, satiety and hunger are just not issues. However, 70% of Americans struggle with weight issues and have proven that they can not control their food intake in this toxic ad libitum food environment. And, the odds are that those who come to me for help (or these forums), this percentage is much higher. Otherwise, they would not be here.
So..
1) If one is trying to lose weight, there are only 3 studies I know of to date in the literature that directly compare the effects of IF vs CR, there is one review comparing the results from separate studies of IF and CR and these studies do not show any advantage to IF (see below). In addition, as noted above, there are several studies that show meal skipping and fasting may not work for many people.
2) If one is trying to lower IGF-1, there is no known benefit to IF over CR in this regard. Focusing on IGF-1 is missing the point. IGF-1 should be the result of our efforts and not the focus. In addition, if the reason for lowering IGF-1 is to impact cancer, then lowering IGF-1, which is only a marker, is not the same as lowering cancer risk or incidence. However, a total lifestyle program that included regular exercise and a low fat, near vegetarian diet (without IF), did lower IGF-1 levels and impact cancer cell growth and the progression of some types of cancer (breast, prostate). This does not mean it will impact cancer cell growth and the progression of all and any cancer.
http://www.ncbi.nlm.nih.gov/pubmed/12588089
http://www.ncbi.nlm.nih.gov/pubmed/16094059
It is proposed that one of the benefits of this way of life that lowers the IGF-1 is both the reduced protein intake and the amino acid profile of the protein on this program.
http://cebp.aacrjournals.org/content/11 ... 1.abstract
3) If one was interested, the best way to incorporate the potential benefits of CR & ON that also addresses the issues of satiety and hunger, is through the understanding and application of the principles of calorie density and the MWL program.
4) If one is on a CR'd version of this program and is trying to fine tune it to see if there is some potential additional benefits to incorporating IF as part of their CR'd program, then that is fine, but first, they really need to understand and implement the basics of calorie density/MWL into their lives first.
Which bring us right back to my original point....
"Bottom line, following the recommendations here to consume a unrefined unprocessed plant based diet that is low in calorie density, high in nutrient density and high in satiety, along with the proper amount and type of physical activity may be the most important issue. Whether someone does this in 3 meals vs 5 meals vs 1 meal, may be less important than total calories and overall food choices, and a fine detail that would be up to the individual based on which method helps them incorporate the more important principles."
In Health
Jeff
In all studies the outcome was the same: No significant differences in weight loss, or changes in body composition.
1) Am J Clin Nutr. 1989 Aug;50(2):248-54. Evaluation of an alternating-calorie diet with and without exercise in the treatment of obesity.
http://www.ncbi.nlm.nih.gov/pubmed/2667313
2) Int J Obes (Lond). 2011 May;35(5):714-27. doi: 10.1038/ijo.2010.171. Epub 2010 Oct 5. The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women.
http://www.ncbi.nlm.nih.gov/pubmed/20921964
3) Intermittent versus daily calorie restriction: which diet regimen is more effective for weight loss? Varady KA. Obes Rev. 2011. Jul;12(7):e593-601. doi: 10.1111/j.1467-789X.2011.00873.x. Epub 2011 Mar 17. Review. PMID: 21410865
http://www.ncbi.nlm.nih.gov/pubmed/?term=21410865
4) Menopause. 2012 Aug;19(8):870-6.
Short- and long-term effects of continuous versus intermittent restrictive diet approaches on body composition and the metabolic profile in overweight and obese postmenopausal women: a pilot study.
http://www.ncbi.nlm.nih.gov/pubmed/?term=22735163