Sleep is Really, Really Important!

canstockphoto15729484In a new journal article Alyssa Lundahl and Timothy Nelson look at how poor sleep quality and quantity affect the human drive to eat.

The take home message is if you don’t sleep well – try to get help as is has a big impact on your food choices in many ways.

Biologically, researchers have found that disrupted sleep can lead to a 20% increase in the amount of calories people eat and that portion sizes are bigger.  It appears that 2 hormones control most of this higher drive for food.  Lower levels of Leptin (tells our brain we how  satisfied we are with what we’ve eating) are found in stressed adults with disrupted sleep and higher levels of Grehlin (tells our brain we are hungry) occur.  This makes people look for more foods that are sweet, salty or starchy.  Researchers have found other hormones also are changed with poor sleep including cortisol, insulin, glucocorticoids and these also make us change our food choices.

If we don’t sleep well, our ability to think is reduced in several ways and can lead to adults and children eating more foods and for children looking for higher calorie snacks.  Poor sleep affects a part of the brain that helps us with goal directed behaviours and being able to moderate our impulses and emotions.  So it is harder to talk yourself into doing healthy goals like going for a walk, eating more vegetables and harder to say no to tempting higher calorie foods.  Another part of our brain is disturbed with poor sleep, making the brain want more rewards to pleasurable stimuli – so we want that pleasurable sensation from tasting of sweet or  fatty foods more than usual.

Poor sleep affects our emotions.  You are more likely to notice negative events and negative emotions and be emotionally distressed when you have slept poorly. I don’t think it would be a surprise to many people that when feeling negative emotions, adults and children tend to eat more foods. The changes in eating patterns are eating less fruit, vegetables and breakfast cereals and eating  more sugary or high fat foods.

The way humans behave is changed when sleep quality or quantity is poor.  Adults and children are more likely to behave impulsively and plan less when they are tired. So when you are tired it is harder to resist tempting foods if you have an impulsive personality and you will tend to eat more food then you may have wanted or planned to.

So if you are trying to make healthy eating or lifestyle changes, try to get enough undisturbed sleep so that you won’t have extra hormonal, thinking, behavioural and emotional challenges.

Regards and best wishes from sunny Brisbane,  Cathie Lowe Accredited Practising Dietitian

Journal Referance:

Alyssa Lundahl and Timothy D Nelson

Journal of Health Psychology June 2015 Vol 20 6 794-805

Beetroot Juice – Recent Study

Many thanks to my client that asked me about beetroot juice and cycling.  If you are a keen cyclist check with your Sports Dietitian before filling your drink bottle with beetroot juice!  It may not meet all your fluid and performance goals.   In June this year, the Journal Med Sci Sports and Exercise published an article on beetroot juice and cycling time trial performance.  It was a preliminary study as it only had 9 athletes in the trial.  It was a randomised trial meaning that for one experiment athletes were given 500mls of beetroot juice and for the next trial 500mls of nitrate-depleted beetroot juice.  The study did show an improvement in cycling performance for a 4km and 16.1km cycling time trials of 2.8% and 2.7%.  The big question now is will the results be the same when a larger group of athletes try the same experiment?  Are there any side effects of drinking 500mls of beetroot juice just before a cycling time trial?  Love to hear any experiences if you have tried this already.

Does Caralluma fimbriata extract help with weight loss?

I was asked about this herbal extract recently.  It’s being marketed in a weight loss supplement at the moment. 

Caralluma fimbriata is extracted from an edible cactus that is grown in India.  It is marketed as an appetite suppressant that will help people lose weight.  In the supplement on the market in Australia the dosage is 6g of Caralluma fimbriata.

So let’s talk about the research available on this extract. 

Remember that in the pharmaceutical industry a drug cannot be sold until there are several long term studies.  A good solid study would have at least 1500 volunteers with at least half receiving the active study drug, half receiving a placebo “non active” tablet, with the side effects closely monitored and results documented for at least 1 year.

There was one study on humans that ran for 60 days.  Fifty overweight volunteers were in the study with half receiving placebo. The dose of the extract was 1g per day.    The study found that there was a significant drop in waist measurement and appetite and a trend of weight loss that wasn’t statistically different between groups.

The only other study was on 18 rats.  The rats were given two different types of food (pellets or pellets and “cafeteria style food”  and given differing doses of Caralluma fimbriata for 90 days and there was an effect on appetite on the 3rd week of taking the extract in the highest dose and less weight gain in those receiving Caralluma fimbriata.

Bottom line:
This extract may or may not help with weight loss, there’s not enough research. There haven’t been any long term studies to show what kind of weight loss could occur and be sustained at 1 year.  Side effects are unknown at this stage.  It is constantly amazing how herbal extracts can be marketed as helping with weight loss with very small research studies compared to the medications that a doctor can prescribe.
Journal Nutrition Metabolism  2010: 2010:285301 Antiobesogenic and Antiatherosclerotic Properties of Caralluma fimbriata Extract

Appetite 2007 May 48 (3) : 338-44  Effect of Caralluma fimbriata extract on appetite, food intake, and anthropometry in adult Indian men and women.

Brown and White rice and Diabetes Risk

Recent Study looking at Brown or White Rice and Diabetes Risk

I’ve had lots of questions and comments about this one and the study was only published on June 14!

If you already have diabetes, this study does not apply.  If you eat rice and already have diabetes the main things to think about are portion size (think small), low glycaemic index (basmati or doongarra rice) and health benefits (brown rice has more fibre and B vitamins).

This study was looking at people without diabetes and whether their rice eating pattern raised or lowered their risk of getting type 2 diabetes.  (White rice, brown rice and the risk of type 2 diabetes in US men and women.  Archives Internal Medicine 2010 June 14 170 (11) 961-969.

The study looked at the long term eating patterns of health professionals in America (39 765 men and 157 463 women).  The key findings were:

– Eating five or more serves of rice per week gives a 17% higher risk of developing type 2 diabetes then people that ate less than 1 serve of white rice per month.
– Eating brown rice, two or more times a week, reduces the risk of developing type 2 diabetes by 11%.  This was compared to people that ate brown rice less than once a month.

So if you don’t have diabetes and want to reduce your risk of developing diabetes, as you get older, brown rice rather than white rice would be a healthy option.  

Cooking tips – brown rice takes longer to cook so plan ahead and get the rice cooking first before preparing a stir fry.  Brown rice has a nutty texture which takes a while to get used to but very enjoyable.