Current Dietary Guidelines and Concerns

Food Guidelines Evolution

• Food guidelines have evolved since 2007, emphasizing dietary variety, dilution to lessen negative impacts of certain foods, and moderation regarding fat, sugar, salt, and calories.
• Balanced proportions are crucial for a healthy diet.

Dietary Reference Intakes (DRI)

• DRI is a general term for dietary standards in the US and Canada.
• It includes key components:
  • Estimated Average Requirement (EAR)
  • Recommended Dietary Allowance (RDA)
  • Adequate Intake (AI)
  • Tolerable Upper Intake Levels (UL)

Current Dietary Concerns

• Processed foods make up 60% of the US diet.
• A low percentage of US adults are metabolically healthy.
• Obesity rates are high: 42% of adults and 19% of children are obese.
• Diabetes/pre-diabetes affects 50% of adults.
• Chronic diseases are rising in younger generations.
• Global deficiencies exist in Iron, Vitamin E, and Calcium.
• Portion sizes have increased significantly over the past 40 years.

Fats and Lipids

Types of Fats

• Saturated Fatty Acids: Solid at room temperature; full of hydrogen; found in whole milk and coconut oil.
• Monounsaturated Fatty Acids: One double bond; includes Omega-9; common in olive oil and canola oil.
• Polyunsaturated Fatty Acids: Multiple double bonds; includes essential fatty acids (Omega-3 and Omega-6); found in sunflower oil and fish.

Trans Fats

• Created through hydrogenation.
• Naturally present in dairy (4-6%).
• Common in processed foods and margarines.
• Artificial trans fats are associated with health concerns.

Fat Digestion Process

• Mechanical breakdown in the mouth.
• Emulsification.
• Lipase action from the pancreas.
• Bile acid involvement.
• Absorption into the lymphatic system.
• Bile acid recycling (97%).

Lipoproteins and Fat Metabolism

• Lipoproteins (HDL and LDL) transport fats through the bloodstream.
• HDL returns excess cholesterol to the liver.
• Maintaining healthy cholesterol levels is important.

Role of Fats

• Energy source (9 kcal/g).
• Protection for organs.
• Energy reserve.
• Precursor for eicosanoids, phospholipids, bile acids, and steroid hormones.

Fat Sources in Foods

• High-fat foods: Donuts, butter, and fatty meats.
• Moderate-fat foods: Milk products.
• Low-fat foods: Whole grain products.
• Oil composition varies:
  • Olive oil: mostly monounsaturated.
  • Coconut oil: mostly saturated.
  • Canola oil: mostly monounsaturated.
  • Sunflower oil: mostly polyunsaturated.