Eat to Thrive Podcast #12: The anti-diet episode
If you've been a regular listener of this podcast, you may have the distinct impression I'm not a big fan of dieting. You would be 100% correct.
I've gone out and called this the anti-diet episode.
I really wanted to present some information about dieting that isn't talked about often, so you can make a more informed choice as to whether you want to jump back on the New Year's diet train this year, or break out of diet prison once and for all. Call it my late Christmas gift to you!
Changing your eating behaviour (usually via the latest fad diet, or even just calorie restriction) for the sole purpose of losing weight, carries with it a 95% chance of failure within 2-5 years. Yes, that's right; around 95% of all dieters will be back to their pre-diet weight during that time, with between one-third and two-thirds of those people ending up heavier than when they started dieting. Dieting is essentially a predictor of weight gain! There is so much evidence to support this, it's called Level A evidence, which is the highest level of evidence available in science. If you're still not convinced, check out page 123 of the "Systematic review for the management of overweight and ob*sity in adults, adolescents and children in Australia" document from the National Health and Medical Research Council website.
For an excellent (and more readable summary), click on the image below to go to Louise Adams' Untrapped website, where you can download her awesome e-book collaboration with Fiona Willer for free. This book busts the top ten myths of dieting, and is chock-full of supporting evidence.
If the news that dieting predicts weight gain in the long term is news to you, you may be feeling quite confronted. What about all those weight-loss studies that publish great results?
Most people on diets will lose weight no matter which diet they are on, be it keto, paleo, raw food, clean eating, detox, or whatever is the latest and greatest fad. Weight will be lost due to fewer calories eaten. Now this weight loss will usually peak around the 6-month mark, and coincidentally this is when the results of weight loss studies are often published. It's what happens after this magical 6-month mark that we don't see in the (often diet industry funded) research, as there is often little follow-up of the participants in these diet studies. At about this time, the whole dieting thing starts to bite you in the bum - obsessively keeping track of everything you eat, sticking to a rigid meal plan, or following whatever weird food rules your favoured diet has, well it just becomes a total drag. Depending on how far down that rabbit hole you go, it can also affect your social life, your relationships with loved ones, and it certainly won't be helping your relationship you have with your body and with the food you eat. Your body also has a few tricks up its sleeve in response to this calorie restriction - increasing hunger signals, slowing your metabolism, and a decrease in non-exercise physical activity levels to conserve energy. These decreases in metabolic rate and spontaneous physical activity (known as NEAT, or non-exercise activity thermogenesis), persist even after weight regain, contributing to the likelihood of a weight regain "overshoot", and a trend for continued weight gain over time.
The gradual weight regain that commonly occurs after this magical 6-month mark often results in the dieter blaming themselves for failing on the diet, when it's actually the diet that has failed them. Ask yourself, if dieting worked, why is it a worldwide, multi-billion-dollar industry? Surely if there was "one diet to rule them all", no-one would ever have to write another diet book, and Jenny Craig and Weight Watchers would go out of business. Instead, you are left thinking you just didn't try hard enough, you weren't disciplined enough, or it just wasn't the right diet for you, and you start looking for the next best diet and do it all over again. This yo-yo dieting, or weight cycling, actually increases the risk of cardiovascular disease, even amongst so-called "normal weight" individuals.
Briefly going back to my comments about the multi-billion-dollar diet industry and the continual search for the next best diet... capitalism exploits insecurities. The diet industry, along with the beauty industry, are prime examples of this in action. Women and girls (and increasingly men and boys) are commonly plagued by insecurities, particularly around their bodies and the way they look. Actually, anyone who doesn't conform to the current societal ideal in terms of body size and shape, or beauty standards, likely experiences similar insecurities. An example of this is the pressure that African-American women feel to chemically relax or heat-straighten their hair, because their characteristic tight natural curls just don't sit within the current narrow perceptions of beauty in Western culture. Wonderfully, there is a movement gaining traction encouraging black women to embrace the natural beauty of their hair, a movement championed in the United States by the awesome Tracee Ellis-Ross.
The role of social media
These days, any feelings of insecurity are further magnified by social media, where celebrities and "influencers" post photoshopped and idealised images of themselves and their lives. A systematic review of 20 studies published in 2016 found that photo-based activities like posting photos of yourself or scrolling through Instagram, had quite a negative effect on body image. These magnified insecurities are a driver for consumerism. If the dominant narrative is that a person is "not enough" or "less than", they will seek out products that promise to "fix" them, and when that product doesn't get the desired result, there will be another product, and another...sound familiar? This is exactly how the diet and beauty industries make so much money. Check out this very short animated film by Lauren Greenfield, where she explores the topic.
But what about the health risks of being overweight?
This is when the data gets even more interesting...
There's a lot of scary talk about the increased mortality risk (risk of dying) from having a higher BMI, or Body Mass Index. BMI is a very blunt tool, designed back in the 1830's by the Flemish astronomer and statistician, Lambert Quetelet. From 1959 through to the early 1990's, BMI was used by the insurance industry in the United States to determine risk.
BMI is a simple mathematical formula of weight in kilograms divided by height in metres squared. The figure you get after making that calculation will put you into one of four categories: underweight, normal weight, overweight or ob*se. Now I have two important points to make here; firstly, I don't like the word ob*se. I think it's an example of stigmatising language, and I personally don't use it - I'm only using it here because all of the BMI charts I have seen use it. Secondly, often you will see the "normal" BMI weight range labelled as "healthy" weight. I have a big issue with this too. BMI is not a good indicator of health status. BMI can't differentiate between bone, muscle and fat, and gets completely silly when you look at adults who have a lot of muscle - take a body builder, an All Black, or any other elite athlete for example. It also has difficulties with those who are very short, very tall, and with people of different ethic backgrounds. Some ethnicities have greater health risks at lower BMI's, while others have lower risk at higher BMI's.
Health status is dependant on many, many variables, and there is plenty of research that shows health behaviours are far better indicators of risk than your weight.
One study of over 20,000 adults in the United Kingdom looking at the top four health behaviours - not smoking, being physically active, moderate alcohol consumption, and eating five or more serves of veg and fruit a day - showed huge decreases in mortality risk as more of these behaviours were followed. The combined effect of all four behaviours was equivalent to an extra 14 years of life. This benefit was consistent across all BMI ranges. In fact, when comparing people in the over 30 BMI category not following any of the health behaviours, those in the same category who had adopted all four health behaviours had a four-fold reduction in mortality risk. But then it does make sense that you can make significant improvements in your health by focussing on behaviours that support you health...but this research demonstrates these benefits hold for people in larger bodies.
It's also important to note that the social determinants of health, including poverty, poor housing, lack of education, social exclusion and unemployment, have a signifiant impact on mortality risk, and these factors are largely out of the individual's control.
As for the 18.5-24.9 BMI range often being labelled "healthy", a study published in 2016 of over 250,000 US adults actually found a lower mortality risk amongst those categorised as overweight. After adjusting for smoking and pre-existing diseases, overweight adults had around a 20% lower mortality risk than normal weight adults. There was also a systematic review published in 2013 of 97 studies covering 2.8 million individuals that concluded being in the overweight BMI category was associated with a 6% lower mortality risk. As for the grade 1 ob*sity category (30-34.9 BMI), a systematic review and meta-analysis from 2013 found this was not associated with higher mortality. However, this review did find a significant increase in risk for individuals with a BMI of 35 and above, but bear in mind this review didn't include any data on lifestyle behaviours, it just looked at BMI measurements. It would be really interesting to be able to look at the four lifestyle behaviours I mentioned before within that BMI category, to see the effects.
As you age, weighing more can also be an advantage - by having a bit more "to spare", you are better positioned to fight off illnesses that might otherwise knock you really hard.
The impact of weight stigma on health
In summary, your honour, this focus on weight as a good indicator of health leads to people in larger bodies being discriminated against every day. This weight stigma has a profound effect on the mental and physical health of those in lager bodies. It can even mean those in larger bodies avoid seeking medical care for health issues, for fear of receiving "the talk" from their GP.
Add to this the idealisation of the thin body in media and society in general, and its no wonder millions of people, larger bodies or not, embark on various weight-loss diets. This is especially so in January, the month where marketers of weight-loss diets go into overdrive, as New Year's resolutions are made.
Now I fully support anyone who wants to overhaul their eating habits to improve their health - I work with clients in my practice to do just that! Its when eating habits are changed solely for the purpose of losing weight I get nervous. Considering the tiny percentage of people that achieve long-term weight loss from dieting, a weight focus can really backfire. If your sole focus is the number on the scale, you risk discarding any health-improving changes you've made if the number doesn't change the way you want it to. The same goes for exercise - if you're only exercising to lose weight you're missing the big picture, along with all the wonderful benefits to be had from regular physical activity.
Dieting also increases your risk of developing an eating disorder, not to mention the very real risk of putting your life on hold until you reach your goal weight. Think of all the amazing experiences you could be missing out on...
The keto diet has reached peak crazy...
You may also be at risk of other health issues if you follow one of the many fad diets currently doing the rounds. There's no way I have time to go through them all here (and if I tried this would be a VERY long blogpost!!), but I do want to take a closer look at the diet I have been asked about the most in 2019.... the keto diet. No prizes for guessing that though, it's been everywhere! It's the most Googled diet of 2019, and seems to be all anyone has been talking about. It's even managed to corner valuable supermarket shelf space, with highly-processed and expensive keto food products popping up in your local.
Where did the keto diet come from, anyway?
The Ketogenic diet was originally developed in the 1920's to help children with refractory epilepsy, where seizures just can't be controlled with medication. On the diet, around 90% of all energy comes from fat, with the rest mostly from protein, with a tiny amount of carbohydrates. The Ketogenic diet is highly restrictive, can be quite unpleasant due to the fat content, and it's very hard to stick to. It must be formulated by a Dietitian, designed specifically for the patient, and the patient must be monitored by a specialist medical professional as well as the Dietitian. Notice I used the term "patient"? This is because the Ketogenic diet is a medical nutrition therapy, only intended to be administered by a Dietitian.
Because the Ketogenic diet is so restrictive, supplementation with various micronutrients will be essential. Side-effects of the diet can include dehydration, fatigue, constipation, stomach upset, vomiting, weight loss and elevated cholesterol levels, although this last side-effect can vary between individuals due to many other factors.
The modern, diet-culture version of keto is a slightly different beast. You'll still be eating a lot of fat (anything from 50-80% of the energy in your diet), likely quite a bit of protein, and a little carbohydrate. Keto diet staples include shellfish, fish, nuts, seeds, meat, poultry, eggs, cheese, coconut oil, avocado, spinach and broccoli (and of course those highly processed and expensive keto foods I mentioned before). Sounds pretty expensive too, and I'm not that confident about the likelihood of regular bowel movements...
Keto proponents wax lyrical about the weight loss benefits of the diet, but studies show little difference compared to other calorie-restricted diets in the long-term; that is, weight loss peaks at around the 5-6 month mark, and is not sustained.
My major concern with the keto diet is that in order to maintain ketosis, you have to eliminate many foods that have proven benefits to health - most fruits, many vegetables, legumes, all breads and cereals, and most dairy products. For example, we know that dietary fibre from wholegrain reduces our risk of heart disease, stroke, type 2 diabetes and bowel cancer. In addition, due to all the nutrient-rich foods you'll be cutting out of your diet, there's a significant risk of vitamin and mineral deficiencies. There's even a risk to kidney health if you already have kidney issues.
There is conflicting evidence around the effect of the keto diet on the fats in your blood - "good" and "bad" cholesterol, and triglycerides. if your particular keto diet includes a lot of saturated fat (fat from animal foods like meat and dairy), it's more likely to increase your "bad" cholesterol levels. Other factors like your genetic makeup, ethnicity, and conditions like type 2 diabetes may also impact how the cholesterol levels in your blood are affected on a keto diet, so it's really important to have your cholesterol levels measured before you make any dietary changes, and regularly monitored by your GP.
Following a keto diet may also decrease the number and diversity of your beneficial gut bugs - your microbiome. We are becoming increasingly aware of how important these little critters are to our overall health, so depriving them of fibre from plant foods (aka their food) doesn't seem such a good move.
There have also been large studies published in 2013 and 2018 showing low carbohydrate diets were associated with increased mortality, so these diets may well shorten your lifespan too! If you are still deathly afraid of eating carbohydrates, here is a link to a great article by one of my nutrition heroes, Dr Tim Crowe.
For those who want some more to read on the keto craze:
The keto diet explained - Vox magazine
What is the Ketogenic Diet? - Academy of Nutrition and Dietetics
Keto diet incredibly risky for kids - Insider
The truth about carbs - National Health Service (NHS)
Here is a wonderful article written by a young girl on the problems of BMI as a health measure:
Tessa Embry - Vox
...and this fantastic article by activist Ragen Chastain:
In summary, my 4 Top Tips for surviving the tidal wave of diet-culture BS this January would be...
1. Try your very best not to be tempted into starting another diet.
They so often follow an all-too-familiar pattern of food restriction, food obsession, a bit of weight loss in the short term, then weight regain and feelings of failure.
Do you really want to go there?
2. Instead, treat your body with respect.
Eat a variety of nourishing foods that will provide your body with the nutrients it needs to do all the amazing stuff it does, and move it everyday in a way you enjoy (not as a punishment for eating a certain food, or to "earn" your food).
3. Celebrate body diversity.
Bodies come in all shapes and sizes. If you are able to eat a variety of food from all four food groups, and regular do some exercise you enjoy, then it's likely your body will be the shape and size that is right for you. Wear your body with pride.
4. Perform a social media cleanse.
If you are following accounts on the social that make you feel bad about yourself, press that "unfollow" button, Who needs that negativity in their life? That crap isn't real anyway.
Take care of yourself, and have a wonderful diet-bullshit-free summer.