Think type 2 diabetes is just a consequence of being overweight? Think again, and you might have to, if you’re 40+, been a regular exerciser or athlete, don’t appear overweight - and have just been diagnosed as pre- or type 2 diabetic…
Type 2 diabetes mellitus (T2DM) is characterised as impaired insulin secretion and/or insulin action (insulin resistant)1. Insulin is the hormone your pancreas produces in response to excess sugar in your blood, and its role is to move the sugar which isn’t needed immediately, to various storage sites for later use when energy availability is low. This sugar is converted to glycogen for storage in the muscles and liver, and lipids for storage as fat. The liver can store excess glucose as both glycogen and fat.
Carbohydrates provide the quickest source of energy for the body to use, with the breakdown of proteins and fat being slower. The more processed carbohydrates, sometimes referred to as ‘simple’ or ‘refined’ carbohydrates, will raise your blood glucose more quickly than ‘unprocessed’ or ‘complex’ carbohydrates. This is because the refining, or processing, strips the fibre from the food, making them less complex and easier for the body to breakdown and release their sugars into the blood stream more quickly. This can be measured in terms of a food’s glycaemic index (GI) or glycaemic load (GL), which rates various foods according to how quickly blood sugar rises on eating them2. This should, however, be used as a guide only, as blood glucose response can be different in everyone.
Blood sugar, whilst necessary for energy, is also highly inflammatory at excessive levels - the body can only cope with about one teaspoon of sugar circulating in the blood at any time3. Foods with a higher glycaemic index will raise blood sugar more rapidly, so a higher amount of insulin will be released to match it. Insulin-resistance occurs when insulin is being released but fails to remove the sugars from the bloodstream, often due to the storage sites being full or the pancreas being unable to produce the amount of insulin required. This causes sugars to recirculate in the blood, as measured by a HbA1c test, which is also a marker of inflammation.
Diabetes is not simply about high blood glucose and energy – it’s a potentially whole-body, life-limiting disease, causing issues with pregnancy and prostate, amongst others, but can be reversed by changing eating behaviours.
Note that HbA1c levels can rise if you’re dehydrated, have iron deficiency anaemia or have recently trained excessively4, so a blood test should always be repeated. Different ethnicities also tend to have higher HbA1c readings5, so results should be interpreted according to context. Your HbA1c result is likely to rise as you age, and it’s also affected by family genetics.
If you’re an athlete, or a regular exerciser, you’re likely aware of the need to ‘keep your blood glucose up’ – ie. have enough circulating blood sugar for immediate use to produce energy for the duration and intensity of your sport. In the ‘80s, the emphasis was all about reducing your fat intake under the misguided notion that fat makes you fat and clogs your arteries, and increasing your carbohydrate intake because this kept you full and was ‘healthier’. It also coincided with the marathon-craze, where Mars and Lucozade/Gatorade became major sponsors and a Milky Way was “the sweet you can eat without ruining your appetite”6. Bread, pasta and rice became the staples of the active person, along with the notion that you could eat what you wanted because you would ‘burn it off’ with exercise. It’s interesting to note that since then, obesity has increased at an alarming rate, T2D diagnosis has risen and is being diagnosed at an earlier age, and it’s now – finally - being accepted that you can’t run off, or train off a bad diet. It might keep you looking lean, but what about the visceral fat building up..?
But as an athlete, you have a ‘healthy’ diet, right? You have your muesli, granola or bran cereal for breakfast, you’ve switched to brown bread in your sandwiches - or even sourdough during Covid – and you’ve swapped white pasta for wholemeal and sweet instead of white potatoes at your evening meal. You might have a take-away or ice-cream for dessert only once a week or drink alcohol only at weekends; you snack on the healthy fruit and nut bars with ‘extra protein’ and you regularly eat fruit, because that’s good for you. You’ve incorporated yogurt and kefir into your diet, as that feeds your gut. Right? Maybe not, and definitely not if you’ve been diagnosed with blood glucose dysregulation…
And that’s because most of what you were told – and are still are being told – is not correct. The diet I’ve described above screams ‘SUGAR’!
Most of the food on the supermarket shelves is so over-processed now, it’s very high in sugar and low in nutrients, as these have been stripped away in the processing. In fact, wholemeal bread has a higher GI at 71, than table sugar itself (GI of 68)7. And because of this over-refinement of our food, most of the flavour has also been stripped away, so sugar is added to compensate for this. Sugar is also added to foodstuffs to help prolong their transit and shelf-life: sugar is a potent preserver - but not of human health.
And then there’s the labelling laws, which are far from transparent: ‘healthy’, ‘lite’, ‘flavour’, ‘natural’, ‘contains protein’, ‘added vitamins and fibre’ can mean absolutely nothing, other than to convince you to buy them. Even John Harvey Kellogg, back in the 19th Century, promoted his cereals with the slogan “breakfast is the most important meal of the day”8. Vitamins or fibre wouldn’t have to be added if the food wasn’t so processed to start with. And when you see a product labelled ‘low fat’ (going back to my earlier point, and likely what you’ve been told to eat if you have high cholesterol), it’s going to be full of sugar instead. Yogurt or kefir, unless it’s plain, is likely to have added sugars in the form of fruit flavourings. And unless it contains ‘live’ bacterial cultures, it won’t be any good for your gut either.
We’re encouraged to ditch the fizzy pop for ready-made smoothies full of natural fruit, and swap sugar for ‘natural’ sweeteners instead. But fruit, containing fibre, polyphenols, vitamins and minerals, is only good for us in limited quantities – it’s still sugar, albeit natural, at the end of the day. One to two pieces is fine, but look how many pieces of fruit are in one of those ready-made, shop-bought smoothies, not to mention all the chemical stabilisers to keep it from going off on the shelf. And research shows that sweeteners, even the so-called natural ones, cause us to seek/crave more sugar due to delivering the taste, but not the energy of natural sugar9.
The next time you pick up a packet of plain crackers, coleslaw, soup carton or yogurt, read the label (if your eyesight is good enough – another deterrent?). If you see any of the following, it’s all hidden sugar: dextrose, fructose, maltose, glucose, sucrose, lactose, sucrose, galactose, maltodextrin, coconut sugar, honey, agave nectar/syrup, barley malt, high fructose corn syrup, brown rice syrup, molasses, treacle.
And then there’s the energy needed for your sport. Carbohydrates do breakdown more easily and quicker than protein and fat, so can be very useful for high intensity training or endurance exercise at high to moderate levels for 60 minutes+10. But you don’t need to have lots of quick-release carbohydrate before or after a long, steady walk, Pilates or yoga session, or gentle swim. That’s because you’re unlikely to need energy fast, so it can be converted from stored fat instead. And if you do feel you need additional carbohydrate, eat it in the form of low glycaemic index foods such as green leafy vegetables (spinach, broccoli, kale, cauliflower, bok choy, green beans). Broccoli is a carbohydrate and very different in terms of the nutrients, calories and its effect on blood glucose, compared to a croissant! A limited amount of root vegetables and grains can be eaten before/after higher intensity/longer duration exercise, although these should, if possible, be avoided altogether initially.
And forget the ‘halo effect’ - you don’t necessarily need to reward yourself post-exercise with a smoothie or a treat, ‘because you’ve worked it off’…it’s just excess sugar and excess calories, especially if the intensity hasn’t been high or long enough. If you want some post-exercise protein, eat a couple of eggs, some yogurt or some plant-based protein (and make sure that isn’t over processed either).
Eating every meal or snack which includes protein and fat will help keep blood glucose levels and insulin release steady. Regular snacking will constantly raise blood glucose throughout the day, so you’re better off eating bigger meals containing low glycaemic index foods with healthy fat and/or protein, than having smaller meals and snacking in between. Ensure you eat enough at each meal – you’re likely to lose weight without the calorie dense, sugary foods, which may be a problem if you’re already lean. Your metabolism will adjust in time but you may have ‘flu-like withdrawal symptoms from sugar initially, along with headaches and fatigue. Drink plenty of water to help mediate this.
Try to leave at least three hours between eating, although this may have to be adapted around your training intensities. If you do need to snack, have a handful of unflavoured, unroasted, unsalted nuts or mixed seeds, some hummus and crudities, a boiled egg, sliced apple or pear with nut butter spread or some live yogurt and berries.
And be aware of the bars, chews, gels and sports drinks you may be using whilst training. Whilst they can be very useful to keep blood glucose levels steady, it’s easy to over-consume them during your exercise session, and they don’t necessarily contain the most wholesome ingredients. Caffeine, for example, is a useful stimulant partly because it raises blood glucose fast11. Try to find the brands which contain natural ingredients, without too much processing or excess sugar added, or better still, make your own: that way you’ll know exactly what ingredients and in what quantities will be in there. Read the labels on shop-bought products, rather than simply believing the marketing claims. Note that Mars changed their strapline to ‘Work. Rest. Play Longer’ in an attempt to associate the bar which aids exercise!12 And be aware that fructose, a staple ingredient in many ergogenic aids, can cause an upset tummy13 and is utilised by the liver differently to other sugars, so often a ‘dual-source’ carbohydrate can be more effective14.
All the above can be summarised in one sentence: avoid all over-processed and beige foods. Unfortunately, these are what we’re offered first and foremost due to the way food is produced now, marketed and displayed on the shelves. It can take some effort to find the more natural, wholesome foods, and remind ourselves how to cook them. And it takes longer to eat them too – all that chewing! But eating slower helps digestion, enables our satiation process to kick in earlier and means we sit down to eat, chat and relax. And when we’re relaxed, our blood glucose is more stable too.
If you’re an athlete and diagnosed with blood glucose issues, you won’t be able to produce energy effectively during your sport. Regulating your blood glucose in your every-day life first, is an absolute must if you want to perform well.
Interested in learning more? Contact Amanda for one-to-one advice, and watch out for a webinar coming soon on ‘Diabetes and How to Reverse it’.
References.
1. Harris, George D. MD, MS; White, Russell D. MD, FACSM. 2012. Diabetes in the Competitive Athlete. Current Sports Medicine Reports 11(6):p 309-315, DOI: 10.1249/JSR.0b013e3182751007
3. Wasserman DH. Four grams of glucose. 2009. Am J Physiol Endocrinol Metab. 296(1):E11-21. doi: 10.1152/ajpendo.90563.2008. Epub 2008 Oct 7. PMID: 18840763; PMCID: PMC2636990.
4. Flockhart M, Nilsson LC, Tais S, Ekblom B, Apró W, Larsen FJ. 2021. Excessive exercise training causes mitochondrial functional impairment and decreases glucose tolerance in healthy volunteers. Cell Metab. 4;33(5):957-970.e6. doi: 10.1016/j.cmet.2021.02.017. Epub 2021 Mar 18. PMID: 33740420.
5. Cavagnolli G, Pimentel AL, Freitas PA, Gross JL, Camargo JL. 2017. Effect of ethnicity on HbA1c levels in individuals without diabetes: systematic review and meta-analysis. PloS one. 13;12(2):e0171315.
7. Unwin D and Unwin J. 2014. Low carbohydrate diet to achieve weight loss and improve HbA1c in type 2 diabetes and pre-diabetes: experience from one general practice. Practical Diabetes, Volume 31, Issue 2, pp76-79. https://doi.org/10.1002/pdi.1835.
9. Yang Q. Gain weight by "going diet?" 2010. Artificial sweeteners and the neurobiology of sugar cravings: Neuroscience. Yale J Biol Med. 2010 Jun;83(2):101-8. PMID: 20589192; PMCID: PMC2892765.
10. Galloway S, Lott M, Toulouse L. 2014. Pre exercise Carbohydrate Feeding And High-Intensity Exercise Capacity: Effects Of Timing Of Intake And Carbohydrate Concentration. Int J Sport Nutr Exerc Metab. 24(3):258–266.
11. Guest N et al. 2021. International Society of Sports Nutrition Position Stand: caffeine and exercise performance. J Int Soc Sports Nutr. 18:1.
13. Prado de Oliveira E and Burini R. 2014. Carbohydrate-Dependent, Exercise-Induced Gastrointestinal Distress. Nutrients. 6(10): 4191–4199.
14. Furuyashiki T, Tanimoto H, Yokoyama Y, Kitaura Y, Kuriki T, Shimomura Y. 2014. Effects of ingesting highly branched cyclic dextrin during endurance exercise on rating of perceived exertion and blood components associated with energy metabolism. Biosci Biotechnol Biochem. 78(12):2117-9. doi: 10.1080/09168451.2014.943654. Epub 2014 Jul 31. PMID: 25080121.