#361 - AMA #74: Sugar and sugar substitutes: weight control, metabolic effects, and health trade-offs

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In this “Ask Me Anything” (AMA) episode, Peter explains how to evaluate sugar and its substitutes in the context of health. Peter explores the role of sweeteners in three common use-cases – beverages, protein supplements, and sweet treats – and breaks down how our evolutionary craving for sweetness now clashes with today’s food environment. He examines whether sugar is uniquely fattening, the hormonal effects of sugar consumption, and the significance of timing in sugar intake. The episode compares natural versus refined sugars, sugar in beverages versus in solid foods, and the pros and cons of popular sweeteners including saccharin, aspartame, sucralose, allulose, and sugar alcohols like erythritol and xylitol. With a focus on weight management, glycemic impact, gut health, and long-term safety, this episode offers a comprehensive guide to navigating the sweetener landscape with clarity and nuance.

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We discuss:

• A quick tangent on chess and parenting [2:30];
• Overview of key scenarios for evaluating sugar and sweeteners [6:15];
• Why humans are hardwired to crave sweetness [13:30];
• Evaluating whether sugar is uniquely fattening or more harmful than other macronutrients under isocaloric conditions [15:15];
• Why sugar drives appetite: low satiety, insulin response, and reward system activation [18:45];
• How sugar type, liquid vs. solid form, and processing level influence appetite and metabolic impact [20:15];
• Addressing the common belief that natural sugars are healthier than refined sugars [26:00];
• How the timing of sugar consumption alters the body’s metabolic response [29:15];
• How Peter advises patients on sugar intake, factoring in metabolic health, insulin sensitivity, and activity level [34:45];
• The most common sugar substitutes, their sweetness relative to sugar, and their caloric content [36:30];
• Evaluating the role of sugar substitutes in weight control: efficacy vs. effectiveness and limitations in study design [40:15];
• Assessing the real-world impact of sugar substitutes on weight, and the role of sweetness without calories [44:00];
• The impact of sugar substitutes on glycemic control [47:30];
• Are microbiome changes from artificial sweeteners substantial enough to cause obesity and diabetes? [50:30];
• How Peter advises patients on the use of sugar substitutes across different contexts [52:30];
Allulose—a sweetener with unique satiety and glycemic benefits and potential for weight control [57:15];
• Emerging evidence that stevia, monk fruit, and sugar alcohols may provide modest metabolic benefits compared to sugar [1:03:00];
• Sugar alcohols explained [1:04:15];
• Sugar alcohols and GI issues [1:05:00];
• Xylitol’s dental health benefits and considerations for use [1:06:30];
• Artificial sweeteners and cancer risk: evaluating evidence, the aspartame controversy, and the role of dose in toxicology [1:07:15];
• Sugar substitutes and cardiovascular disease: assessing flawed studies and the absence of direct risk evidence [1:11:00];
• Why artificial sweeteners seem to attract so many negative headlines [1:12:45];
• Balancing benefits and risks of sugar substitutes: guidance for desserts, beverages, and protein products [1:14:15]; and
• More.

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