Dr Layne Norton: The Science of Eating for Health, Fat Loss & Lean Muscle

Dr. Lane Norton on Nutrition, Fitness, and Energy Balance

• Dr. Lane Norton is an expert in protein metabolism, fat loss, and nutrition
• Holds degrees in biochemistry and nutritional sciences

Energy Balance and Utilization

• Calorie: a unit of energy (heat)
• Food contains potential chemical energy in the bonds of macronutrients
• Digesting, assimilating, and metabolizing nutrients creates energy in the form of ATP (adenosine triphosphate)
• ATP powers various reactions in the body
• Metabolism primarily involves creating ATP through oxidative respiration in the mitochondria
• Hydrogen ion gradient across the mitochondria powers the production of ATP

Calories In, Calories Out

• Calories in, calories out is a complicated concept
• Involves the potential chemical energy in food and how it is converted into ATP
• Understanding energy balance is important for weight loss, weight maintenance, and weight gain
  Krebs Cycle and Energy Metabolism
• Krebs cycle linked to glycolysis in carbohydrate metabolism 
  • Carbohydrates converted to glucose, which goes through glycolysis to produce ATP
  • Pyruvate produced, then converted to acetylCoA, which enters Krebs cycle to produce more ATP
• Protein metabolism
  • Proteins converted to amino acids, used for protein synthesis or converted to glucose through gluconeogenesis
  • Some ketogenic amino acids can also enter Krebs cycle
• Fatty acid metabolism 
  • Fatty acids create energy through beta-​​oxidation, producing acetylCoA for Krebs cycle

Energy Balance and Weight Management

• Energy in vs. energy out 
  • Food labels can have up to 20% error in calorie count
  • Metabolizable energy varies based on individual gut microbiome and food composition
• Energy out components 
  • Resting metabolic rate (RMR): 50–70% of total daily energy expenditure
  • Thermic effect of food (TEF): 5–10% of total daily energy expenditure 
    • Fat: 0–3% TEF
    • Carbohydrate: 5–10% TEF
    • Protein: 20–30% TEF
  • Physical activity: exercise and non-​​exercise activity thermogenesis (NEAT)
    • NEAT: spontaneous, unconscious physical activity (e.g., fidgeting)

NEAT and Obesity Resistance

• Obese-​​resistant individuals tend to have higher NEAT levels 
  • Spontaneously increase physical activity when overeating
• Significant calorie burn from NEAT 
  • Can range from hundreds to nearly 1,000 calories per day
• Study by Levine (1995)
  • Metabolic ward study with participants overeating by 1,000 calories per day for six weeks
  • On average, participants gained weight and fat mass
  • Some individuals gained less than expected due to increased NEAT levels
    Neat (Non-​​Exercise Activity Thermogenesis)
• Anecdotally, some people seem to expend more energy through Neat 
• Neat is the most modifiable aspect of energy expenditure
• 10% reduction in body weight can lead to a decrease in Neat of almost 500 calories per day

Weight Fluctuations and Discouragement

• Weight fluctuations can discourage people from weight loss
• To track weight loss accurately, weigh in every morning after using the bathroom and take the weekly average
• Compare weekly averages to track progress

Fitness Trackers and Caloric Burn

• Fitness trackers overestimate energy expenditure by 28–93%
• People may think they’re eating in a calorie deficit but not lose weight due to inaccurate measurements from fitness trackers

Post-​​Exercise Induced Increase in Oxidative Metabolism

• There is a small increase in metabolic rate after exercise
• However, it is not significant enough to make a difference in weight loss
• High-​​intensity interval training (HIIT) may increase basal metabolic rate, but when equating work between HIIT and moderate or low-​​intensity cardio, there is no difference in body fat loss
• Different forms of exercise may affect appetite differently, impacting calorie intake
  Exercise and Calorie Considerations
• Different forms of exercise can affect calorie burn, appetite, and lean muscle mass 
• Exercise can be broken down into different dimensions
• Calorie trackers may not be completely accurate, but can be useful for comparison within an individual
• Tracking steps can help maintain non-​​exercise activity thermogenesis (NEAT) levels during fat loss diets

Placebo Effect and Exercise

• Placebo effect can change physiology and be as powerful as some pharmaceuticals
• Beliefs about exercise and supplements can impact outcomes, such as strength and lean body mass
• Exercise has been shown to have an appetite suppressant effect and improve biomarkers of health independent of weight loss
• Exercise is considered the best thing for health span and lifespan, outweighing other potential health interventions
  Effects of Exercise on Weight Loss and Appetite
• Constrained energy expenditure model 
• Exercise increases sensitivity to satiety signals 
  • People who lose weight and keep it off for years often engage in regular exercise
  • Exercise may help regulate appetite more appropriately
• Classic study from the 1950s in Bengali workers 
  • Sedentary workers ate more food than lightly or moderately active workers
  • Heavily active workers compensated for calories burned through exercise
• Effects of exercise on appetite likely at the brain level 
  • Blood sugar regulation may not be the main driver of appetite
  • Hypoglycemia can cause hunger, but it’s a different kind of hunger
• Randomized control trials show that exercise may lead to eating less 
  • Individual variability exists; some people may feel hungrier after exercise

Psychology and Physiology of Eating

• Hunger may not be the main reason people eat 
  • People eat for various reasons, such as stress, lack of sleep, boredom, and social cues
• Successful weight loss maintainers often develop a new identity 
  • Example: Actor Ethan Suplee lost over 300 pounds and created a new identity to maintain weight loss
  • Similar to addiction recovery, creating a new identity can help break disordered eating patterns
• Treating disordered eating patterns requires a comprehensive approach 
  • Exercise, increased sensitivity to satiety signals, and addressing psychological factors are all important components
    Daily Process of Change and Weight Loss
• Losing weight and keeping it off is a daily process 
• 6 out of 7 obese people will lose significant weight but struggle to keep it off
• People often focus on the diet and weight loss but not on maintaining the new weight

Importance of Sustainable Diets

• Choose a diet that is sustainable for the rest of your life
• Different forms of restriction work for different people 
  • Nutrient restriction (low carb, low fat)
  • Time restriction (intermittent fasting)
  • Calorie restriction (tracking macros)
• Adherence to a diet is key for long-​​term weight loss

Research on Popular Diets

• Meta-​​analyses show no significant difference in weight loss, fat loss, and biomarkers of health between time-​​restricted eating and non-​​time-​​restricted eating when calories are equated
• No significant difference in fat loss between low carb and low fat diets when calories and protein are equated
• Pick the diet that works best for you and is easiest to adhere to

Switching Between Diets

• No significant downside to switching between diets (e.g., keto for a few months, then omnivore)
• Transition period between extremes (low fat to low carb or vice versa) can cause temporary insulin resistance 
  • Lasts a few weeks
  • Important to be aware of potential discomfort during the transition period I focus on a variety of fiber sources to ensure I’m getting a diverse range of nutrients and supporting my gut microbiome. Some of my go-​​to fiber sources include:
• Fruits: Apples, pears, berries, and bananas are all great sources of fiber. 
• Vegetables: Leafy greens, broccoli, cauliflower, and carrots are fiber-​​rich options.
• Whole grains: Brown rice, quinoa, barley, and whole wheat bread provide fiber and other essential nutrients.
• Legumes: Beans, lentils, and chickpeas are excellent sources of fiber and protein.
• Nuts and seeds: Almonds, chia seeds, and flaxseeds are not only high in fiber but also healthy fats.

By incorporating a variety of these fiber sources into my diet, I can support my gut health and promote overall well-​​being.
Diversity in Fiber Sources

• Fiber is important for longevity 
  • Large meta-​​analysis of over a million subjects showed a 10% reduction in risk of mortality for every 10g increase in fiber
  • Also extended to cardiovascular disease and cancer
• Recommended dose: 15g of fiber per 1000 calories intake 
  • No clear upper limit, depends on individual tolerance
• Fiber sources: fruits, vegetables, whole grains, cereals, etc. 
  • No clear evidence on which source is better

Fiber and Gut Microbiome

• Fiber is good for gut microbiome 
  • Helps with elimination, adds bulk to stool
  • Effects on mortality more important than elimination
• Saturated fat may not be great for microbiome 
  • Reduces prevalence of positive strains of bacteria
  • Bile end products that combine with saturated fat have negative effects on healthy gut microbiota

LDL Cholesterol and Heart Disease

• High HDL cholesterol is a marker of metabolic health 
  • People with high HDL usually have good biomarkers of metabolic health
• Mendelian randomization studies show lifetime exposure to LDL has a linear effect on heart disease 
  • LDL can penetrate the endothelium, providing a mechanism for its effect
  • Epidemiology supports LDL as an independent risk factor
• Framingham data shows that high HDL, low LDL has lower risk than high HDL, high LDL 
  • Ratio of LDL to HDL does matter

Interpreting Studies and Changing Opinions

• One study may not be enough to change an opinion, but multiple studies can provide convincing evidence
• Important to consider the context and implications of studies 
  • Data is just data, but interpretation and application can be problematic
• Holistic view of psychology, placebo effects, and core physiology is important for understanding the full picture You’re going to say, “That sounds terrible! Why would I want to do that?” But that’s exercise, and we know that exercise is good for us in the long term. So we have to be careful about looking at acute responses and assuming that they’re going to relate to long-​​term outcomes.

Protein Intake and Distribution

• Protein is the biggest lever for health and body composition 
  • Aim for 1.6 grams/​​kg of body weight, higher if possible
  • No significant downsides to high protein intake
• Protein has a higher thermic effect of food, helps preserve/​​build lean body mass, and affects appetite 
  • Satiety effects depend on the specific food and its processing
• Protein distribution matters 
  • Most people consume 65–70% of their protein at dinner
  • Protein has no significant storage mechanism in the body
  • Balancing protein intake with meal frequency and lifestyle is important

Protein Assimilation and Meal Frequency

• Fasting does not appear to increase protein assimilation
• Studies on protein distribution and muscle growth show mixed results 
  • Some studies show benefits to distributing protein intake evenly across meals
  • Others show no significant difference in lean body mass
• Intermittent fasting (16:8) with 2–3 high-​​quality protein meals during the feeding window may not negatively affect lean body mass 
  • More extreme fasting protocols (e.g., alternate day fasting, 22:2, 24) may have negative effects on lean body mass
  • Resistance training can help mitigate these effects

Takeaways

• Prioritize total protein intake, aiming for at least 1.6 grams/​​kg of body weight
• Distribute protein intake across 2–3 high-​​quality protein meals per day
• Resistance training is crucial for maintaining and building lean body mass, especially when fasting or following extreme diet protocols
  Protein Distribution and Time Restricted Eating
• Mild forms of time restricted eating seem to be fine for maintaining lean body mass 
• Animal studies provide high subject number, control, and duration
• 16:8 intermittent fasting likely fine for most people’s goals (maintaining/​​losing weight, adding muscle to specific areas)
• Timing and distribution of protein intake matters, but total protein intake is more important

Plant-​​Based Diets and Protein

• Building muscle on a plant-​​based diet is possible, but requires more planning
• Difficult to get enough protein without going over on total calories
• Isolated plant source of protein is helpful for bioavailability and leucine content
• Soy, potato protein isolate, and plant-​​based whey are good vegan protein sources
• Adding free leucine to plant-​​based protein sources can improve muscle protein synthesis
• Options for vegans: use isolated protein sources, add free leucine, or use blends with high leucine content (e.g. corn)
  Plant-​​Based Protein and Muscle Building
• Plant-​​based protein sources can be blended to create complementary blends with essential amino acids 
• Plant-​​based bodybuilders and endurance athletes have built impressive muscle
• Focus on minimally processed foods for health, health span, and lifespan

Processed Foods and Caloric Intake

• Processed foods can lead to spontaneous overeating and increased calorie intake
• Ultra-​​processed foods can increase calorie intake by 500 calories per day
• Not solely due to sugar, fats, or combination of sugar, fat, and salt
• Highly palatable processed foods can be detrimental to body composition goals

Balancing Processed Foods and Individual Goals

• Processed foods can be a tool for those with high caloric needs, such as athletes or teenagers
• Focus on meeting protein, fiber, and micronutrient needs first
• Minimally processed foods can be difficult to consume in high quantities due to gut fill

Sugar Intake and Obesity

• Sugar intake has decreased in the past 20 years, but obesity continues to rise
• Alcohol intake has slightly increased, while smoking has decreased
• Nicotine can act as an appetite suppressant and nootropic, but delivery methods can be harmful

Caloric Intake and Energy Output

• Caloric intake has increased, contributing to obesity
• Energy output has decreased over the years, with fewer people engaging in regular exercise
• Balancing caloric intake and energy output is crucial for maintaining a healthy weight and lifestyle
  Changes in Physical Activity and Diet Over Time
• People are more sedentary now compared to 30–40 years ago 
• Physical education is no longer a requirement in many schools due to budget cuts
• Activity levels are decreasing while caloric intake is increasing or plateauing

Obesity and Personal Responsibility

• Obesity is often seen as a sign of laziness or lack of personal responsibility
• However, factors such as sexual assault trauma, low income, and traumatic childhood events can contribute to obesity
• Addressing habits and behaviors is more helpful than simply telling people to eat less and move more

Sugar and Health

• High sugar intake is often associated with obesity and poor health
• However, people who consume fruit (which contains sugar) do not have the same negative health associations
• The issue may be more related to low fiber intake rather than high sugar intake

Sugar and Body Composition

• A study by Sirwit (1997) found no difference in body fat loss between groups consuming high and low sugar diets when calories, protein, carbs, and fats were matched
• The study also found no significant differences in biomarkers of health between the groups, except for a small difference in LDL cholesterol (likely due to fiber intake)

Sugar and Health Markers

• Meta-​​analyses of studies comparing isoenergetic exchanges of different carbohydrates with sugar (fructose, glucose, sucrose) found no significant differences in health markers like HbA1c, fasting blood glucose, and blood lipids
• This suggests that sugar may not be inherently harmful to health when consumed in moderation and with adequate fiber intake

Restricting Sugar and Disordered Eating

• Restricting specific nutrients can lead to cravings and binge eating
• It’s important to focus on overall dietary habits and avoid creating negative associations with specific foods

Artificial Sweeteners

• Artificial sweeteners are often consumed as a substitute for sugar
• Some people may consume them in moderation, while others may have concerns about their potential health effects
  Artificial Sweeteners and Health
• Artificial sweeteners and non-​​nutritive sweeteners (NNS) can be helpful in weight loss 
  • Replacing sugar-​​sweetened beverages with NNS beverages can lead to improvements in adiposity and health markers
  • NNS beverages can act as appetite suppressants
• Some studies suggest artificial sweeteners may disrupt the gut microbiome, but the overall impact on health is unclear
• Taste buds can adapt to different levels of sweetness, potentially affecting cravings and food choices
• The impact of artificial sweeteners on blood sugar and insulin levels varies depending on the specific sweetener 
  • Aspartame and stevia appear to have little to no effect on blood sugar or insulin
  • Saccharine and sucralose have mixed results in studies
• The benefits of artificial sweeteners may depend on the individual’s situation and health goals 
  • For obese individuals, replacing sugar-​​sweetened beverages with NNS beverages can be a powerful tool for weight loss
  • For lean individuals without health problems, artificial sweeteners may not be as necessary or beneficial
    Artificial Sweeteners and Health
• Health effects of artificial sweeteners are debated 
  • Some argue they help with weight loss
  • Others argue they have negative health effects
• Unclear if artificial sweeteners are healthier than water 
  • May be beneficial for those trying to lose weight

Microbiome Effects of Artificial Sweeteners

• Some studies show no effect on the microbiome 
  • Shorter duration studies (2–4 weeks)
• Other studies show changes in gut bacteria 
  • Longer duration studies (10 weeks)
  • Example: Sucralose increased a species associated with lower adiposity and better insulin sensitivity
• Overall, some artificial sweeteners may not be metabolically inert 
  • Effects may be good, bad, or neutral

Blood Glucose Responses to Artificial Sweeteners

• Some studies show elevated blood glucose levels with artificial sweeteners 
  • Example: Sucralose group had higher blood glucose at one time point
• Overall area under the curve for glucose response not different between control and sucralose group 
  • Suggests the effect may not be significant

Publication Bias and Personal Choices

• Publication bias towards studies showing effects of artificial sweeteners 
  • Null hypothesis (no effect) is less likely to be published
• One study may not be enough to change behavior 
  • Consider the overall body of evidence
• Personal choice to consume artificial sweeteners like stevia and aspartame 
  • May not actively avoid sucralose based on recent studies