Slow Digesting Carbohydrates for Fat Loss and Better Performance?

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Consume fewer calories, use more body fat and feel great during exercise – these are the claims behind slow digesting carbohydrates. Before you ditch your typical sports drink in favor of a slow digesting carbohydrate, check out the truth behind each of these lofty claims.

In this post I will cover:

  • One big fat myth – slow digesting carbohydrates won’t help you burn body fat
  • Trying to burn fat during exercise is pointless
  • Fast carbohydrates are better for high-intensity athletes
  • Advice for those on a low carbohydrate diet

According to Generation UCAN, makers of a slow digesting starch (a type of carbohydrate), typical high sugar sports nutrition products cause a rapid increase in energy followed by low blood sugar leading to a sharp crash, leaving you feeling tired with a bad case of the munchies (“post-workout cravings” according to their website). Generation UCAN’s starch will keep your blood sugar levels nice and steady while delivering long-lasting energy for hard-working muscles. The payoff? You need fewer carbohydrates (and therefore calories) to fuel activity and your insulin levels (a hormone that helps store body fat among other functions) are kept low so your body can pull from a larger supply of body fat (multiple times larger than the amount of carbohydrate stored in muscle and liver).

All of this sounds great in theory. Yet none of it holds up in real life.

Typical sports nutrition products do not cause a sharp crash (symptoms of low blood sugar) when consumed before or during exercise (1). Instead, your body will use the sugar pretty quickly to fuel hard working muscles (2). What about post-workout cravings? Typical sports drinks, gels and gummies won’t lead to cravings, despite possible changes in blood sugar, even if you consume them when your body doesn’t need them – when you are sitting on the couch scrolling through Snapchat videos (3).

One Big Fat Myth – Slow Digesting Carbohydrates Won’t Help You Lose Body Fat

Trying to burn fat during exercise is pointless (unless you are a ultra distance athlete and therefore relying on large amounts of fat for energy to run for several hours at a time). Otherwise it doesn’t matter if more fat is used during exercise. What matters most if you want to lose weight? The total amount of calories burned over time.

You are better off burning fat while sitting in front of your computer or sleeping then trying to maximize fat used during exercise. Why? Fat is a slow source of energy – if you are seriously tapping into your fat stores during exercise you aren’t exercising very hard and therefore you aren’t burning very many calories. If you want to make the most of your exercise sessions, burning as many calories as possible, you’ll need carbohydrates to help you sustain your exercise intensity. It’s the difference between walking and sprinting. You have to walk for a much longer period of time to burn as many calories as you will if you are sprinting or doing intervals.

Fast Carbohydrates are Better for Athletic Performance

slow digesting carbohydratesCarbohydrates are the best source of energy to keep up with the calorie demand of high-intensity exercise. The less carbohydrate you have stored in your muscle (stored from the carbohydrate you eat each day), the more your body will rely on carbohydrate consumed during exercise in the form of sports drinks, gels, beans, gummies etc. Fast carbohydrates (the mix of sugars in common sports nutrition products) have been successfully used for decades. Yet some athletes get an upset stomach when exercising. Generation UCAN says their product will lower risk of stomach upset. Unfortunately, a well-designed study found athletes actually had greater stomach upset on UCAN (a slow digesting carbohydrate) than they did on traditional sports nutrition drinks (8). If you don’t want the nitty-gritty science, skip the next section and move to the following paragraph.

In this crossover study (each study subject experienced each type of drink) 10 male cyclists consumed 1) 60 grams of carbohydrate from a typical sports nutrition drink (sucrose and glucose blend) 30 minutes before and 60 grams of carbohydrate per hour during exercise (Sports Drink); 2) 60 grams of carbohydrate from UCAN (hydrothermally-modified starch; HMS) before and 60 grams of carbohydrate per hour during exercise (Isocaloric HMS); 3) 60 grams of carbohydrate from UCAN before and 30 grams of carbohydrate per hour during exercise (Low HMS). They spent three hours exercising (one hour at a moderate pace followed by intervals and sprints). There was no difference in performance between the Sports Drink and High HMS. Both the Sports Drink and High HMS resulted in slightly better performance compared to Low HMS (less carbohydrate during exercise). Consuming UCAN, whether 30 or 60 grams per hour, led to greater incidence of nausea compared to consuming 60 grams of carbohydrate per hour from a typical Sports Drink (8).

Typical carbohydrates used in sports nutrition products are digested quickly and used by muscles right away so you can train harder than you would if you relied on slow carbohydrates. The body can use about 30 – 60 grams of carbohydrate per hour, and possibly up to 90 if a mix of different sugars is used. Fat metabolism kicks in after around 20 minutes of aerobic exercise. “After about two hours of continuous endurance exercise, fat is a major source of energy. However, carbohydrate is still essential. Without enough carbohydrate present there is incomplete burning of fatty acids resulting in ketone bodies as a byproduct. When ketones build up, the body’s pH drops (metabolic acidosis) and the body attempts to compensate via respiratory hyperventilation,” states sports dietitian Sally Hara, MS, RD, CSSD, CDE. You won’t improve performance if you consume slow carbohydrates before or during exercise (5).

Fast carbohydrates are also preferential right after exercise – your body can rapidly replenish carbohydrate stores in muscle for use during her next training session. This is very important for athletes who train more than once over the course of an 8-hour period and also important for those who train again less than 24 hours later (6, 7). Anyone who doesn’t train again less than 24 hours later can re-stock their carbohydrate in muscle by consuming enough carbohydrate in their diet from potatoes, rice, quinoa, and other higher carbohydrate foods.

You can function on fewer carbohydrates. However, “there is a difference between functioning and performing your best. Athletes and high-intensity sports to follow a low carbohydrate diet are more likely to get tired early and make mental errors,” states Hara. If you want to perform well and burn more calories while lowering risk of stomach upset, choose a traditional sports nutrition product instead of being swayed by the false marketing promises behind slow digesting carbohydrate products.

 

References

1 Jeukendrup AE, Killer SC. The myths surrounding pre-exercise carbohydrate feeding. Ann Nutr Metab 2010;57 Suppl 2:18-25.

2 Marmy-Conus N, Fabris S, Proietto J, Hargreaves M. Preexercise glucose ingestion and glucose kinetics during exercise. J Appl Physiol 1996;81:853-857.

3 Schultes B, Panknin A, Hallschmid M, Jauch-Chara K, Wilms B, de Courbiere F, Lehnert H, Schmid SM. Glycemic increase induced by intravenous glucose infusion fails to affect hunger, appetite, or satiety following breakfast in healthy men. Appetite 2016;105(1):562-566.

4 Roberts MD, Lockwood C, Dalbo VJ, Volek J, Kerksick CM. Ingestion of a high-molecular-weight hydrothermally modified waxy maize starch alters metabolic responses to prolonged exercise in trained cyclists. Nutr 2011;27(6):659-665.

5 Burdon CA, Spronk I, Cheng H, O’Connor HT. Effect of Glycemic Index of a Pre-exercise Meal on Endurance Exercise Performance: A Systematic Review and Meta-analysis. Sports Med 2016:1-15.

6 Stephens FB, Roig M, Armstrong G, Greenhaff PL. Post-exercise ingestion of a unique, high molecular weight glucose polymer solution improves performance during a subsequent bout of cycling exercise. J Sports Sci 2007:1-6.

7 Aulin KP, Soderlund K, Hultman F. Muscle glycogen resynthesis rate in humans after supplementation of drinks containing carbohydrates with low and high molecular masses. Eur J Appl Physiol 2000;81:346-351.

8 Bauer DA, Vargas F CS, Bach C, Garvey JA, Ormsbee MJ. Slow-Absorbing Modified Starch before and during prolonged cycling increases fat oxidation and gastrointestinal distress without changing performance. Nutrients 2016;8(392):1-16.

Tackling Concussions Head-On: How Nutrition Can Improve Outcomes

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football

I sat on the floor hunched over and crying. My elbows were raised – close to my eyes as my arms hugged my head, hands clenched at the base of my neck. My brain felt like a percussion instrument shaking inside my skull. As the pounding grew more intense the pain became unbearable. I had a concussion, my second in two years, which earned me a night in the ER.

Concussions are common in sports and recreation. Though considered a mild type of traumatic brain injury because they are usually not life-threatening, all concussions should be taken seriously. A single blow to the head can result in short-term loss of brain functioning or long-term changes in thinking, language, emotions and sensations including taste, touch and smell (1). Repeated concussions can be very dangerous and may lead to permanent changes in brain functioning or in extreme cases, death (2). Though widely recognized in football players, concussions happen in all sports – even in everyday activities – and they are occurring at younger ages. Athletes who have had one concussion have a greater risk (2 – 5.8 times higher) of experiencing another concussion (3). Multiple blows to the head could lead to chronic traumatic encephalopathy (CTE), a progressive neurodegenerative disease associated with poor memory, changes in personality, behavior, speech and gait (4). Posthumous examination of some former NFL players in addition to a few college football players who committed suicide revealed CTE. In March 2016, the NFL acknowledged the link between traumatic brain injury and CTE. The movie ‘Concussion,’ set for release in late December, 2015 highlights concussions in former NFL players though the league has gone to great lengths to make today’s game safer.

Decreasing the Damaging Effects from Concussions

Anyone who experiences a blow to their head or body (a forceful blow to the body can cause the brain to shake inside the skull) should be immediately examined by a physician with experience in the evaluation and management of concussions. Though the person may say they feel fine and can continue with regular activities, symptoms of concussion do not always appear immediately and may instead be delayed for several hours. Continuing to play or perform mental tasks like studying can increase severity or symptoms and cause complications including the possibility of developing permanent brain damage.

Symptoms of Concussion may include:

  • Confusion
  • Headache
  • Vision changes
  • Memory loss
  • Difficulty with coordination, clumsiness or stumbling
  • Dizziness
  • Irritability
  • Personality changes
  • Slurred speech
  • Delayed response to questions
  • Nausea or vomiting
  • Sensitivity to light and noise
  • Problems sleeping
  • Seizures
  • Loss of consciousness

In addition to the symptoms that occur soon after a concussion, some people experience Post-Concussion Syndrome (PCS) days or weeks later. PCS can cause many of the same symptoms experienced after a concussion as well as trouble concentrating, apathy, depression and anxiety. Symptoms may last a few weeks. If you suspect PCS, have the patient evaluated by a psychiatrist (5).

Nutrition Management

In addition to rest, following a graduated return-to-play and school protocol, and other steps you should take to treat concussions, emerging research suggests nutrition may play an important role. Certain nutrients seem to help reduce some of the damaging effects from concussions:

Protein: 1 – 1.5 grams of protein per kg body weight per day is recommended along with sufficient calories to reduce the inflammatory response (6).

EPA and DHA Omega-3 Fatty Acids: EPA and DHA, omega-3 fatty acids found in fish and algae, increase fluidity of cell membranes, reduce inflammation and enhance cerebral blood flow (which is reduced for up to a month or longer in athletes that recover slowly) (7). Cell membranes are like gateways allowing substances to enter cells or blocking their entry. When cell membranes are more fluid (and therefore less rigid), they perform better, opening the gate for nutrients to come in. DHA, in particular, makes up 97% of the omega-3 fatty acids in the brain and is essential for normal brain functioning (8). Several animal studies show EPA and DHA supplementation before or after a traumatic brain injury helps limit structural damage and decline in brain functioning (9, 10, 11, 12, 13, 14, 15).

There is no clear consensus regarding optimal intake of EPA and DHA prior to or after a concussion. Given that many Americans do not eat enough fish and an estimated 75% of American diets are too low in EPA and DHA, it makes sense to start by meeting the general guidelines for recommended intake of EPA and DHA by:

  • Consuming fatty fish varieties that contain high levels of omega-3s, including salmon, tuna, mackerel and herring at least twice per week;
  • Take an omega-3 supplement providing EPA+DHA daily (be sure to look for high-quality fish oil, algal oil or krill oil supplements in your local grocery or health store);
  • Eat and drink DHA omega-3-fortified foods and beverages, including milk, 100% juice, and yogurt.

Research has yet to identify exactly how much EPA + DHA may be helpful after a concussion. However, according to the Food & Drug Administration (FDA), doses of EPA + DHA up to 3 grams per day are considered safe.

Zinc is necessary for optimal brain functioning while a deficiency of this mineral may compound oxidative damage from concussions. Though zinc supplementation may be an effective treatment modality, additional research needs to determine if zinc supplementation is safe after concussions. The Upper Limit for zinc is 40 mg per day.

Animal and human studies suggest creatine helps prevent secondary brain injury after traumatic brain injury. However, animal studies show long-term creatine intake may decrease its beneficial effects on the brain after injury. Future research needs to better elucidate the relationship between creatine pre-TBI and creatine post-TBI and outcomes.

Other potential approaches to addressing concussions through nutrition include ketogenic diets which are very high-fat, minimal-carbohydrate diets that are effectively used to decrease both the incidence and severity of seizures in children with epilepsy. Ketogenic diets provide an alternate energy source for brain functioning – ketones derived from the breakdown of fat. This may be important since available glucose, the primary energy source for brain functioning, may be decreased after a concussion.

Current research supports the integration of a dietitian into the team of health professionals treating concussions. Though nutrition interventions are considered preliminary at this time, consideration should be given to nutrition strategies that may reduce long-term effects while causing no further harm.

Disclosure: I am a GOED/Omega-3 Science Advisory Council Member supporting the research behind omega-3 EPA and DHA for a healthy brain, heart and eyes.

References

1 What are the Potential Effects of TBI? Injury Prevention & Control: Traumatic Brain Injury. CDC. http://www.cdc.gov/TraumaticBrainInjury/outcomes.html

Concussion (Traumatic Brain Injury). Pubmed Health.

3  Harmon KG, et al. American Medical Society for Sports Medicine position statement: concussion in sport. Br J Sports Med 2013;47:15-26. http://www.amssm.org/Content/pdf%20files/2012_ConcussionPositionStmt.pdf

4  McKee AC, Cantu RC, Nowinski CJ, Hedley-Whyte T, Gavett BE, Budson AE, Santini VE, Lee H, Kubilus CA, Stern RA. Chronic Traumatic Encephalopathy in Athletes: Progressive Tauopathy following Repetitive Head Injury. J Neuropathol Exp Neurol 2009; 68(7): 709–735.

Post-Concussion Syndrome. PubMed Health 

6 Nutrition and Traumatic Brain Injury: Improving Acute and Subacute Health Outcomes in Military Personnel. The National Academies Press. 2011. http://www.nap.edu/catalog/13121/nutrition-and-traumatic-brain-injury-improving-acute-and-subacute-health

7  Meier TB, Bellgowan PS, Singh R, Kuplicki R, Polanski DW, Mayer AR. Recovery of cerebral blood flow following sports-related concussion. JAMA Neurol 2015;72(5):530-8.

8 Salem N Jr, Litman B, Kim HY, Gawrisch K. Mechanisms of action of docosahexaenoic acid in the nervous system. Lipids 2001; 36(9):945-59.

9 Mills JD, Hadley K, Bailes J. Dietary supplementation with the omega-3 fatty acid docosahexaenoic acid in traumatic brain injury? Neurosurgery 2011;68:474–81

10 Wu A, Ying Z, Gomez-Pinilla F. Omega-3 fatty acid supplementation restores mechanisms that maintain brain homeostasis in traumatic brain injury. J Neurotrauma 2007;24:1587–95

11 Wu A, Ying Z, Gomez-Pinilla F. Dietary omega-3 fatty acids normalize BDNF levels, reduce oxidative damage, and counteract learning disability after traumatic brain injury in rats. J Neurotrauma 2004;21:1457–67

12 Wang T, Van K, Gavitt B, Grayson J, Lu T, Lyeth B, Pichakron K. Effect of fish oil supplementation in a rat model of multiple mild traumatic brain injuries. Restor Neurol Neurosci 2013;31:647–59

13 Mills JD, Bailes J, Sedney C, Hutchins H, Sears B. Omega-3 fatty acid supplementation and reduction of traumatic axonal injury in a rodent head injury model. J Neurosurg 2011;114:77–84

14 Wu A, Ying Z, Gomez-Pinilla F. The salutary effects of DHA dietary supplementation on cognition, neuroplasticity, and membrane homeostasis after brain trauma. J Neurotrauma 2011;28:2113–22

15  Wu A, Ying Z, Gomez-Pinilla F. Exercise facilitates the action of dietary DHA on functional recovery after brain trauma. Neuroscience 2013;248:655–63