All Diets Work…and that’s the Problem
Which Diet is Best? All…and none. Photo: Stuart Miles at FreeDigitalPhotos.net
All research starts as good ideas. And then research validates if those ideas are, in fact, any good. Many ideas can be proven to achieve similar effects, in this case, weight loss or improved health. In other words, there’s more than one way to skin a cat…or lose 20 pounds and improve cardiovascular disease risk.
Company spokespeople cite the “latest” research about their diet and how it’s the best and how no one else’s compares. I politely respond, b*llsh*t. Ask a dietitian, or even trainer, how many times they’ve heard: “What’s the best way for me to eat to lose weight, or get healthier?” Like we’re supposed to magically have the answer…not even the research proves a single “holy-grail answer.” (beyond eat better and move more). But we need to have an answer, because we’re the experts.
So here’s an answer; let’s prove that all diets work, even ones that blatantly contradict each other in approaches:
*Note: This list is long. If you want to skip to the punch line, hit Page Down a few times.
Similar weight loss between a high-protein, low-fat & high-carbohydrate, low-fat diet: http://ajcn.nutrition.org/content/81/6/1298.full
Both low-fat and low-carb diets led to 15 pound weight loss: http://jcem.endojournals.org/content/89/6/2717.short
When total calories are held constant, low-fat and low-carb diets yield similar weight and body fat loss (better insulin, but worse blood lipids in high protein group): http://ajcn.nutrition.org/content/90/1/23.abstract
Weight loss was similar between a high-protein and high-carbohydrate group after an initial 3 months of calorie restriction (better blood pressure improvement in high protein group): http://ajcn.nutrition.org/content/90/5/1203.abstract
Just cutting fat out of the diet works: http://ajcn.nutrition.org/content/53/5/1124.full.pdf
Low-fat, high-fiber diet predicts long-term weight loss and decreased Type 2 Diabetes risk: http://link.springer.com/article/10.1007%2Fs00125-006-0198-3?LI=true
Low-fat diets improve cardiovascular disease risk factors: http://circ.ahajournals.org/content/86/1/1.full.pdf
Lower carbohydrate diets lead to weight loss: http://phdres.caregate.net/curriculum/pdf-files/nejm2k3-2074.pdf
Zone (40/30/30), Atkins (low-carb), Ornish (low-fat) and LEARN (lifestyle-behavior change) all resulted in weight loss. Atkins had best results in 12 months: http://jama.jamanetwork.com/article.aspx?articleid=205916
Those who have achieved significant long-term weight loss tend to consume a low-fat, low-calorie diet (~23% of calories from fat): http://europepmc.org/abstract/MED/9550162
Low-fat, low-carb and Mediterranean diet groups all lost weight, low-carb and Med groups did better: www.fammed.usouthal.edu/JournalClub/Journal%20Club%2032609/WtLossWithLowCarbMediterraneanOrLowFatDiet–NEJM.pdf
A lower-fat diet led to weight maintenance in postmenopausal women over 7.5 years compared to a 4 pound weight gain in the control group: http://jama.jamanetwork.com/article.aspx?articleid=202138
Those following a moderate fat Mediterranean diet had better adherence to the diet than low-fat diets. Average weight loss after two and a half years: 7.7 pounds. http://europepmc.org/abstract/MED/11673773/reload=0;jsessionid=KaU6kHUz52R7Ig82Xxw1.20
Just eating less foods high in fat leads to weight loss, but restricting calories AND fat does better (plus self reported exercise): http://europepmc.org/abstract/MED/8281220
Consuming a reduced-calorie diet across a range of nutrient levels [protein (15 to 25%), fat (20 to 40%) and carbs (35 to 65%)] 424 participants lost a similar amount of weight independent of nutrient composition. Interestingly, 40% of the weight was regained within 2 years, independent of groups as well: http://ajcn.nutrition.org/content/95/3/614.abstract
Meal Replacements work, better than food-based diets initially (28 vs. 20 pounds lost in first 16 weeks)…until the meal replacements stop (12 pound vs. 2 pound REGAIN in the following 24 weeks). www.biomedcentral.com/content/pdf/1475-2891-9-11.pdf
Dairy IS effective for weight loss:
www.euromilk.org/upload/docs/attachments/EDA/Abargouei%20et%20al_2012_%20Dairy%20intake,%20weight%20and%20body%20composition.pdf (In the presence of calorie restriction)
http://ajcn.nutrition.org/content/96/4/735.short (May be beneficial during initial stages of weight loss)
Dairy IS effective for reducing inflammation: http://ajcn.nutrition.org/content/91/1/16.long
Dairy IS NOT effective for weight loss:
Soy IS effective for weight loss:
Soy is effective as a weight loss MEAL REPLACEMENT (btw, tons of research on effectiveness of meal replacements): http://www.nature.com/ejcn/journal/v57/n4/abs/1601587a.html & www.biomedcentral.com/content/pdf/1475-2891-2-14.pdf
Soy and Inflammation:
No indication that soy itself promotes nor fights inflammatory levels: http://atvb.ahajournals.org/content/26/5/995.full
Whole Grains PROMOTE health and weight loss:
Whole Grains and Inflammation:
Equivocal (neither good nor bad): http://jn.nutrition.org/content/137/6/1401.full
Improved systemic inflammation in diabetics: http://journals.lww.com/co-lipidology/Abstract/2007/02000/Dietary_glycemic_load,_whole_grains,_and_systemic.3.aspx
Paleo Diet Improves Weight and Health Biomarkers:
Origins of the recommendations of the Paleo diet (2004): http://www.tc.umn.edu/~gaut0007/Hunter-Gatherer%20Mayo.pdf
Intermittent Fasting is as Effective for Weight Loss as Consistent Calorie Restriction
More Frequent Meals Lead to Better Control of Appetite and Weight:
Most of the weight loss studies above have 3 or more meals per day (snacks, supplements, etc.)
Recap – Here’s the summative review:
All diets work, but the results last ONLY if you stick with them – if your “diet” becomes the true meaning of the word: your permanent eating habits. Some interesting statistics from the studies above:
1. Poor long-term adherence to most diet recommendations: The average dropout rate of participants in these studies were usually somewhere between 25 to 50% with most studies lasting less than 6 to 12 months. Imagine that many people dropped out of your school or quit your job…makes you think people don’t want to be there.
2. Modest long-term results: And studies that lasted longer than a year resulted in modest average weight losses around 5 to 10 pounds.
3. Only 33% use better eating AND exercise for weight loss: In a comprehensive look of over 32,000 people in 1998, nearly one-quarter of men and 38% of women reported trying to lose weight. Unfortunately, only one-third of the people trying to lose weight were actually trying to eat better AND exercise more: http://europepmc.org/abstract/MED/15165656
4. When food is more than just fuel: Few of these dietary interventions take into account people dealing with issues of emotional eating.
This article is one of the best reviews I’ve seen of weight loss for obesity and metabolic syndrome (pre-diabetes, cardiovascular disease, etc.) and their conclusion quote describes the situation well:
“As shown in this review, there are many dietary strategies focused on macronutrient distribution or micronutrient and food-enriched manipulation for the treatment of obesity and features of MetS features. However, the real challenge is to find the appropriate approach for maintaining body weight loss and preventing subsequent relapse, while simultaneously reducing cardiovascular risk factors.
The ideal diet should be personalized to each patient and should include those dietary factors that imbue healthy and satiating dietary habits that are beneficial not only for effective weight loss, but are also good for body-weight maintenance as well as for reducing cardiovascular risk. Thus, a currently available diet may be one that has a moderate protein content (30%), high monounsaturated and omega-3 FAs, low-GI carbohydrates (40%), and includes adequate quantities of fiber, isoflavones, calcium, and antioxidant minerals. Since adherence to healthy dietary patterns can be difficult, meal replacement and dietary supplements should be considered as effective strategies for weight loss, weight maintenance, and treatment of MetS. Several factors such as genetics, physical activity, psychopathological conditions, obesity type, gender, age, or yo-yo cycles may influence the outcome of any dietary intervention. They should be taken into account as much as possible when dietary advice is prescribed for body weight management.”
From: Obesity and the metabolic syndrome: role of different dietary macronutrient distribution patterns and specific nutritional components on weight loss and maintenance (2010) by Itziar Abete, Arne Astrup, J Alfredo Martínez, Inga Thorsdottir, and Maria A Zulet
It’s still a matter of calories in vs. calories out…even if you choose not to count them. The rub is, the equation is always changing on both sides depending on your base metabolism (which tends to decrease if you’re chronically undereating – to be discussed in further posts), your exercise levels and, of course, your eating habits.
Remember the question from earlier about the best diet to lose weight? Here’s a better answer:
There are 10,000 ways to lose weight, but only one of them matters: the one that works for you.