A2E: Fat loss: what the personal trainer needs to know about food, exercise & fat loss

Transcription

1 A2E: Fat loss: what the personal trainer needs to know about food, exercise & fat loss Tony Boutagy Twitter/TonyBoutagy Facebook.com/BoutagyFitnessInstitute Weight loss or fat loss? Energy deficit results in loss of muscle, fat tissue and bone mass; Energy deficit from diet alone is derived from ~60% fat tissue, 40% muscle tissue and 1% bone mass; Presenter has seen DXA results showing 100% of 6kg weight loss derived from muscle tissue (low calories and endurance exercise)! Preserving muscle and bone whilst decreasing fat mass is the holy grail of successful weight reduction programs. Is it possible? Recent research has show it is possible with high protein diet and resistance training 1 How do you measure changes in body composition? DXA scans are the most useful. Does the time of day effect fat loss? For the vast majority of people, fasted vs fed training, matched for identical energy expenditure, exercise in the fasted or fed state results in similar fat loss. HIT performed in the fasted or fed state results in similar fat loss as well. New research on sleeping low (ie with low muscle glycogen) and training without carbohydrate availability shows promise as a potential strategy to promote fat loss 2 The effect of fasted training on mitochondria: fasted exercise is a potent stimulus for mitochondrial biogenesis, FATs and enzymes. 1 Longland et al. Am J Clin Nutr 2016;103: Marquet et al. Med Sci Sports Exerc Jan 7. [Epub ahead of print] 1

2 Does caffeine help? Caffeine (2-3mg/kg/BM) improves exercise capacity when carbohydrate availability is low. Does exercising in the fasted training reduce performance and perceived effort? Humans adapt to performing exercise in energy deficit and with low carbohydrate availability with little reduction in performance, capacity and perceived effort. Is one exercise type better than another for fat loss? Well-controlled research has shown that if energy expenditure is matched, there is no difference in 24-hr fat oxidation between high or lower intensity endurance exercise or resistance training. Is there an optimal intensity at which fat oxidation is maximized? The FatMax test can be used to determine the individuals exercise intensity at which fat burning is maximal. It is highly variable amongst individuals and very difficult to perform. The amount of fat used is highly individual and can range between 0.2g-1.5g of fat a minute during exercise at intensities between 30-80% of VO2peak. Recent studies have found fax oxidation rates to be 2.3 higher in individuals who fat adapt over those who chronically consume a high carbohydrate diet 3 Does high-intensity exercise oxidize fat? Originally thought to not be an important factor during the session but significantly increases energy expenditure both during and after the session, potentially contributing to 24-hr energy deficit and potent stimulus for mitochondrial growth. New data suggests that welltrained individuals have a much greater capacity to utilize fat as a fuel during high-intensity exercise 4. Does EPOC oxidize fat? EPOC can increase energy expenditure ~30% of the amount expended in the training session over the next ~24 hours. Are there supplements that increase fat oxidation? 3 Volek et al. Metabolism Mar;65(3): Hetleild et al. BMJ Open Sport Exerc Med

3 Not really. Caffeine, green tea and coffee might help and won t harm! The effect is not as big as you think, unfortunately. All other legal supplements/ fat burners do not work. No one pill or supplement can exert remotely comparable benefits to one single session of exercise! What are the effects of strength training on fat loss? When matched for energy expenditure, it is the same as endurance training. But is a potent protector of muscle tissue. Is fat loss purely about lowering insulin via a low carbohydrate diet? Although insulin is involved in fat gain/fat loss, energy balance (and being in negative energy balance) is a stronger driver of fat balance than insulin levels. Does insulin resistance interfere with fat loss? Studies have shown that insulin resistant subjects have reduced capacity to oxidize fat both during and after exercise, decreased fat mass reduction on a hypocaloric diet and respond best to daily exercise and <40% of energy derived from dietary carbohydrate diets. Does insulin resistance effect glycogen storage and triglyceride production? Yes, insulin resistant individuals have reduced glycogen storage capacity and increased TG production. Does exercise training improve insulin resistance? Exercise improves glucose uptake ~30% and shows a two-fold increase in glycogen storage in the insulin resistant. Does diet need to be modified if insulin resistant? Studies suggest that dietary carbohydrate should be ~40% or less of energy needs. What drives fat gain: excessive energy intake vs excessive carbohydrate consumption? Currently the most controversial of all areas in obesity research. The majority of data indicates that over consumption of total energy coupled with reduced physical activity drives the obesity epidemic and not over consumption of one macronutrient (carbohydrate). 3

4 Recent research has demonstrated negative caloric balance (via exercise and diet) was the driver of fat loss and not the overall composition of the diet 5 ; Reduction of highly palatable, energy-dense, highly addictive, unsatiating foods that stimulate hunger, appetite and over consumption should be the primary goal of the nutrition intervention! Are there problems with being in prolonged energy deficit? Endocrine dysfunction, decreased T3 levels and reduced metabolic rate. All problems resolve when you do not sustain energy deficit for more than 5 days (you must regularly return to energy balance every week, see below). What is the role of dietary protein and resistance training when in energy deficit? Protein and resistance training rescue muscle mass when in energy deficit resulting in larger loss of fat mass and preservation of muscle tissue. What are the ideal strategies to create sustainable energy deficit? Daily planned exercise limit rest days (if you need them, you are potentially training too hard); Daily non-planned physical activity; 3-5 low-intensity exercise sessions with low carbohydrate availability (fasted); 1-2 higher-intensity exercises sessions in the fed state; 2-3 strength training sessions to preserve muscle mass; Option A: 5:2 (5 days eating ~metabolic rate and using exercise to create an energy deficit and 2 days [weekends] to remain in energy balance) Option B: 2:5 (2-3 days of marked caloric deficit [a third of energy needs], high protein intake [2g+/kg/BM] and weight training with Parr et al. Obesity (Silver Spring) Mar 2. doi: /oby [Epub ahead of print] 4

5 days of unrestricted healthy eating, regular protein distribution/amount to stay ~energy balance; Emphasize foods rich in protein and those with high satiation potential; Emphasize foods rich in dietary fibre, nutrient value, minimally processed and enjoyable, diverse, colourful, pleasurable and sustainable! 5