‘Pie hole’, colloquial for one’s mouth, is believed to have evolved in the USA in the 1980s from the British expression ‘cake hole’ (coined in the mid 20th century). Pie hole refers to a mouth, as in: Shut your pie hole or, in this case: Put less in your pie hole.

Wednesday, December 19, 2018

Being Held Up By Keto Bandito?

The keto diet is so popular right now for weight loss... It seemed only fitting that I return from maternity leave with a topic shrouded in controversy. Dieters and wannabe nutrition "experts" tout this diet for weight loss and fat burning. But does the science agree?

Below is Q&A about the keto diet. I hope I've buttered you up enough to chew the fat with me as we explore the fats... I mean facts.

Question #1 - What is the origin of the ketogenic diet?
The ketogenic diet was originally developed as medical nutrition therapy for children with epilepsy. Further, some research shows a keto diet may benefit people with certain cancers, and neurological conditions. In these cases, the diet is administered as therapy under the guidance of a dietitian and doctor.

Question #2 - What is ketosis?
"Keto" is a super cool name, who wouldn't want to say they're on the keto diet? It's almost as catchy as gluten-free. But what is ketosis? To understand it we need to rewind, get a little technical, and understand some physiology:
  • Our brain needs carbohydrates for energy
  • Glucose is the simplest carbohydrate, and the brain's preferred energy source
  • When we decrease our carbohydrate consumption dramatically (to ~20g of carbs per day) our body uses up its glucose stores (glycogen)
No, you're not in ketosis yet.
  • Your body is using amino acids (the building blocks of protein) to create glucose, a process called gluconeogenesis (remember for later)
  • The body is no longer able to manufacture a compound called oxaloacetate, needed for normal fat breakdown via the Krebs/Citric Acid Cycle 
    • Insufficient oxaloacetate means another compound, called acetyl-CoA, builds up 
    • Acetyl-CoAs interact with each other and form ketone bodies: acetoacetate (AcAc), β-hydroxybutyric acid (BHB) and acetone
    • Ketones are formed in the liver but the liver cannot actually utilise them for energy
      • Amino acids are used to create new glucose (gluconeogenesis, remember?)
      • Glycerol is also used to make new glucose, glycerol is liberated during the breakdown of triglycerides (fats stored in your body)
    • Ketones can cross the blood brain barrier and are used as an alternate energy source
Bottom line: The process of producing ketones and remaining in ketosis is complex and requires very strict and precise carbohydrate (and protein) restriction.
Question #3 - Is it hard to maintain ketosis?
Yes. The classic keto diet requires 4% of calories come from carbohydrates, 6% from protein, and 90% from fat. That's <20g of carbs per day. To put that in perspective, it is currently recommended that 45-65% of calories should come from carbohydrates (>50% whole grain), 10-35% from protein, and 20-35% from fat.

There are a variety of keto diet adaptations, however, in my research for this article it's clear that larger amounts of carbs and protein hinder ketosis.
Unlikely to keep you in ketosis

It's really difficult to achieve and actually maintain ketosis. Keto is a very restrictive diet, requiring precise monitoring and weighing of foods. Too many carbs means the citric acid cycle can function normally to break down fats without producing ketones (described in Q#2). Too much protein and your body will convert the amino acids into glucose (gluconeogenesis).

Bottom line: Chances are higher than not that you are not actually maintaining ketosis.

Question #4 - Is ketosis beneficial for weight loss?
Yes, BUT... 

There is significant weight loss at the onset of the keto diet (up to 10lbs in 2 weeks). This is due to water loss (glucose is stored with water, water is heavy.) Most people want to lose fat, not water. No one ever asked "do I look watery in this outfit?"

Due to the restrictive nature of the keto diet, long term compliance is low. Meaning dieters "fall off the bandwagon", and it's well documented weight regain is common in such scenarios. Think about it... you go back to eating normally, glycogen stores are replenished... glycogen contains water, remember? 

Some research shows greater weight loss with the keto diet compared to other diets. This research is specific to obese patients with ongoing physician monitoring.

Bottom line: The keto diet, if maintained beyond 2 weeks often does result in weight (and eventually fat) loss, but the cost is high - see Q#6. And there's a difference between weight loss and fat loss.

Question #5 - How does ketosis help with weight and health?
These are some proposed mechanisms of action:
  • Appetite reduction due to the satiating effect of protein, effect on hormones controlling hunger, the possible effect ketones have on suppressing hunger (1, 2, 3)
  • Reduced lipogenesis (creation of fats) and increased lipolysis (fat breakdown) (1, 2, 3)
There is research documenting possible improvements in blood pressure, insulin sensitivity, and glycemic control.

Bottom line: The exact way weight/fat loss is achieved isn't fully understood, it's likely a combination of factors. 

Question #6 - Are there side effects to the keto diet?
Yes. Ranging from constipation to malnutrition. Deficiencies in calcium, vitamin D, selenium, magnesium, phosphorus, iron, essential fatty acids and prebiotics. Both constipation and deficiencies are due to the scarcity of fiber-containing foods that also contain vitamins and minerals (fruits, vegetables, whole grains, and legumes.) 

Many research papers and articles written by experts cite the importance of monitoring renal (kidney) function. How many of your gym buddies do this?

Ketones raise the pH of blood and a side effect of this is the removal of calcium from bones, called demineralisation which, over time increases the risk of osteoporosis. 

Another side effect is high levels of LDL cholesterol - the "bad" cholesterol (1, 2). This is not a surprise when one's diet is a scoop of fat with a side of fat.

Bottom line: Eating meat, butter, and oil will leave you
Insert face-palm emoji
constipated and lacking many vitamins and minerals needed to maintain proper health and function. Such high-fat diets tend to contain large amounts of saturated fat...BOOM, high LDL cholesterol.

Question #7 - Should you start or continue the keto diet?
To keep this somewhat unbiased, instead of answering the question, here's a checklist to ask yourself:
  1. Is it enjoyable to follow a very restrictive diet?
  2. Do you want to cut out things you enjoy eating?
  3. Think about what you know of a healthy diet. Does it seem healthy to eat huge quantities of fat and miniscule amounts of other things that have stood the test of time like fruit, veg, whole grains, legumes?
If I were answering this checklist, here are my dietitian-biased answers:
  1. Blech, no. I don't want to weigh my food, count my calories, or cut my carbs.
  2. Hell no. I love foods from every food group, especially chocolate (that's a food group, right?)
  3. Umm, no. I do not regularly eat sticks of butter.
    You're probably not...

Wednesday, July 25, 2018

Are You Into Intermittent Fasting?

Intermittent fasting is a hot-button topic, and a popular trend in the weight-loss arena. A recent study shed some light on the science and efficacy of such a dietary pattern. So, should you fastidiously fast the fat away?

As usual, there's more to the story than the click-baity article titles fooling you with follies for fast fat loss.

Intermittent fasting is a broad term covering diets including: 
  • Start-stop eating where people fast completely for 24 hours once or twice a week
  • The 5:2 diet where participants choose one or two non-consecutive days and consume only ~500kcals on those days and eat normally on the other days
  • The 16/8 pattern where people eat only during an 8 hour window, the other 16 hours are fasted
This last pattern involving the 8 hour eating window is where we'll wander today.

A new study found that participants who followed this eating pattern for 12 weeks had the following results compared to those following their usual diets:
  • An approximate 3% loss of body weight
  • An approximate kcal deficit of 300kcal per day (hence the above weight loss)
  • Participants reduced their eating window on average by 3 hours (from 11 to 8 hours)
    • Though research shows only 15% of adults have an eating window <12 hours 
  • A significant decrease in systolic blood pressure 
A few other noteworthy mentions:
  • This study was performed with an obese population
    • Meaning results are not applicable to other populations (eg: normal-weight or overweight individuals) without more research
  • This diet pattern involved no calorie counting
    • A great thing considering counting calories is often inaccurate, time-consuming, not sustainable for a long period, and creates a preoccupation with food
  • The feeding window in this study was 10am-6pm
  • Participant adherence to this eating pattern was positive
    • Meaning this type of dietary pattern shows promise of being sustainable over a long period, compared to alternate-day fasting (like 5:2), or ridiculous diets like "no sugar" or "no chocolate" that cause rebound-like effects when dieters inevitably "fall off the wagon"
  • Compared to other forms of intermittent fasting, this period of time restriction produced a lower energy deficit (meaning less weight was lost) 
    • For example: emerging evidence shows alternate-day fasting produces a deficit of 25-30% of daily calories compared to the time-restricted window that produced ~20% deficit
    • The likely reason is that alternate-day fasting requires strict monitoring and calorie counting where time-restricted fasting does not, as the saying goes "work smarter, not harder"
  • Other cardiometabolic factors (eg: glucose control, insulin sensitivity, triglycerides, cholesterol levels) didn't reach statistically significant levels of improvement 
    • However, the obese population studied had baseline cardiometabolic markers within normal ranges. Therefore, it's quite possible that repeating this study in obese people whose markers are abnormal would see improvement
Lastly, we can't have a conversation about time-restricted eating, as exhibited in this study without mentioning the body clock (circadian rhythm). A previous Pie Hole article details the research on our internal rhythm and how it is impacted by the time of day we eat, drink, and sleep. The timing of food has flow-on effects that can alter metabolism and the microbiome. Research shows a shorter eating window (of <12 hours) helps improve sleep quality, weight loss, weight maintenance, and energy levels.

What are the take home messages?
  1. Shortening your eating window to <12 hours can have many health benefits including higher sleep quality, this in turn impacts metabolism and hormones related to hunger, thus weight
  2. Shortening your eating window is sustainable:
    • It doesn't require calorie counting or strict "dieting" which can lead to a preoccupation with food, increase the risk of disordered eating, and lead to weight regain
    • Long term sustainability means greater adherence to the eating pattern, less "falling off the bandwagon", more positive and long term results 
  3. Put less in your pie hole during a window of 12 (or less) hours per day

Thursday, May 17, 2018

Don't Forget to Exercise

You already know there are a multitude of benefits to exercising. You may not know quite the extent and reach of these benefits. Wait for it... Well, maybe run for it...

Several new studies investigated physical activity and it's relationship to cognition. As we get older, we tend to have more "senior moments" or "tip-of-the-tongue" moments where we can't quite remember something but we know we know it. Instead of flopping your fingers over the keyboard typing into Google, it's time to get those flabby arms 'a flapping!
One study found that healthy older adults have more of these "senior moments" compared with young adults. This may also happen to new mothers... Been there.
But seriously, here's a brief overview of several recent studies showing your brain's health is linked to exercise:
  • One study found physical activity intensity was associated with improved performance on several cognitive assessment tasks
  • Another study found that higher aerobic fitness levels decreased the probability of "senior moments" in healthy older adults
    • This study further demonstrated a link between aerobic fitness and language functioning in older adults
    • Perhaps a fit older person could write me a funny joke about hemorrhoids and steroids?
  • A study investigating adults with mild cognitive impairment found subjects receiving cognitive exercises, physical exercises, and music therapy had significantly improved levels of cognition compared to the control group (no intervention) whose cognitive status significantly worsened
    • Yes, that means the exercise/intervention group's mild cognitive impairment improved, while the no-exercise group's got worse
  • Another study found the duration of exercise (>1 hour/day) increased cortical thickness in various areas of the brain 
    • Thinning of these areas is associated with age-related deterioration and Alzheimer's Disease
    • Interestingly, frequency and intensity were not associated significantly with cortical thickness (in this study)
    • The study also found a benefit to education level preventing cortical thinning
Since we're talking about brains. I wanted to pour a little nutrition into this piece too: an article released this week found eating a higher quality diet (you know, one that includes lots of fruits, veg, fish, nuts, whole grains, dairy, and limits sugary drinks) correlated to larger brain volume than those who ate poorer quality diets. Also noteworthy is that our brain volume declines with age, so high quality diets may help slow this process, keeping our brain younger.

What did we learn?
  1. Don't forget to exercise (get it?)
  2. Exercise and a high quality diet can help keep our brains from expiring prematurely 
  3. This research adds to the existing (aged) body of evidence (see what I did there?) that brain health is tied to external factors like diet and physical activity
Here's a good place to get started if you're looking to get more physically active.

Thursday, April 12, 2018

One Easy Thing You Can Do to Prevent Weight Gain

In the battle of the bulge, there is one easy thing dietitians tell their clients that they CAN do, rather than focus on all the things not to do and not to eat. Though, personally I like to make the liberating statement "don't 'diet', restrict, or count calories", these behaviours are totally counter-productive to health and enjoying life (truly, research says so.)

You're dying to know the secret, right? Well, the secret is: It's not a secret, it's not a gimmick, it's not hard, it doesn't cost anything, and YOU already control it. Ready?

Chew more and eat slower!

Too simple? But not really. A recent study of more than 59 thousand people compared "fast", "normal", and "slow" eaters. The findings are fascinating, worth sinking your teeth into (slowly - get it?)
  • Stats of the slow-eating group:
    • Significantly higher number of women
    • Lower average BMI (22.3kg/m2)
    • Lower number of obese people (21.5%)
    • Smaller average waist circumference (80.1cm)
    • Consumed less alcohol, and less frequently
    • Lower number of habitual smokers
  • Facts from the fast-eating group:
    • Significantly less women
    • Significantly higher average BMI (25.0 kg/m2)
    • More obese people (44.8%)
    • Larger average waist circumference (86.8cm)
Proposed reasons for this association are that eating slowly and chewing helps increase feelings of fullness and satiety before an excess amount of food/calories are consumed. There's a whole complex system of hormones and gut bacteria at play here.

The study found that decreasing eating speed can lead to reductions in BMI, waist circumference, and obesity.

Two more things the study found to help curb weight gain:
  1. Not eating after dinner
  2. Not eating within two hours of sleeping
Avoiding these help reduce excess body weight. Studies have found people who snack after dinner and within two hours of sleeping have a higher likelihood for metabolic syndrome.

A few points to tie this all together:
  • Dieting, restriction, and rules around food cause more problems than they solve: Often leading to a preoccupation with food, an increased likelihood of binge eating, weight regain, psychological problems, yoyo dieting, and development of disordered eating patterns. Further reading here, here, here
  • Lack of sleep wrecks havoc with hormones that are related to food consumption like hunger, fullness, and metabolism
  • Mindfulness or "intuitive eating" are terms that crop up in the above articles. Basically, savouring and enjoying your food includes eating more slowly and being "present". This kills two birds with one stone: Eating slower and taking the time to really enjoy your meal/treat without depriving yourself
Food and eating are enjoyable parts of the human experience. Memories with friends and family usually stem from social time involving food. Taking a straw and sucking the fun out of food... sucks...

Wednesday, February 14, 2018

Feed Your Brain Fish, Stand By for Superior Slumber

This article focuses on two things: Sleep and fish. They're kind of unusual and slippery bedfellows, so to speak. But swim with me, and sleep soundly... It might help your waistline and you brain.

What if I told you the frequency of fish consumption improved sleep quality? What if I told you, these two together have beneficial long-term cognitive outcomes? Feel like a salmon swimming upstream? Don't worry, the facts are packed like a tin of sardines.

Ok, but first... You, and scientists, already know a few things about fish:
  1. They contain long-chain omega-3 essential fatty acids
    • DHA and EPA (docosahexaenoic acid and eicosapentaenoic acid)
  2. They're an excellent source of lean protein
  3. They contain iodine, vitamin D, and antioxidants
  4. Eating fish 2-3 times a week is currently recommended for good health
  5. Fish during pregnancy is not only great, it's encouraged (more on that here and here)
  6. Certain fish are high in methyl-mercury (read about that in the links at bullet 5 above)
Expanding on some of these, here are a few things you may not know:
  1. DHA and omega-3 fatty acids may play a role in melatonin (sleep hormone) production (1, 2)
  2. DHA and EPA play a critical role in the growth and function of neural tissue
  3. The children of pregnant women who ate fish (or took supplements - see more about supplements here) during pregnancy had improved neurodevelopment functions including eye and hand coordination, language and visual motor skills, IQ, and cognitive and academic performance (in adolescences)
  4. Omega-3 intake is associated with reduced cognitive decline and dementia in older adults
So the study in question regarding sleep and fish examined the fish eating habits of school-aged kids (9-11 years old), also their sleep quality (higher sleep quality meant fewer sleep disturbances), and cognition (IQ).
Findings showed that kids who ate fish more regularly (once or more than once per week) had significantly fewer sleep disturbances, therefore higher sleep quality, compared to their peers who seldom or never ate fish. The fish-eaters also had increased verbal, performance, and full scale IQ scores (almost 5 points higher). Scaling the intellectual ladder may actually involve scales (because fish have scales... get it?)

What's the bottom line?
Fish intake on a frequent basis may improve sleep quality, resulting in more favourable long-term cognition.
The other important connection here is the link between sleep, academic performance, and obesity... Not a new concept, especially given all the policies around feeding kids breakfast at school to improve academic performance. But let's connect the dots for fun:
  • Poor sleep and lack of sleep negatively impacts learning, academic performance, and memory (1, 2)
  • Lack of sleep increases the risk of weight gain and obesity through a variety of factors including changes in circadian rhythm (body clock), microbiome, and metabolism (1, 2, 3, 4)
Taken together, here are some tips:
  • Kids, adults, parents, pregnant ladies, grandparents: Eat fish 2-3 times per week
    • Aids with cognition, supplies essential omega-3 fats, and may also improve sleep
  • Choose low mercury fish as an excellent source of lean protein
    • This can displace fatty meats or processed meats that add significant calories and known carcinogens
  • Get enough sleep at every age (1, 2)
    • Improves cognition, learning, obesity/weight management
If you've got a bone to pick, grab life by the fish tail and swim to it!