Why Do We Need Lipids?: Videos & Practice Problems

Which of the following correctly lists the energy density (kcal per gram) for fat, carbohydrate, and protein respectively?

The AMDR (Acceptable Macronutrient Distribution Range) for fat intake in adults is best described by which of the following statements?

A student plans to eat 2,400 kcal/day and reports consuming 80 grams of total fat. Does this plan meet the fat AMDR (20–35%)? Show your calculation and conclusion.

Calculate the percent of energy from fat for a 2,200 kcal/day diet that includes 100 grams of fat. Indicate if the diet is within the AMDR and explain.

Which analysis best explains why dietary fat is more efficient for long-term energy storage than carbohydrate?

A researcher wants to model how a chronic small excess of calories will affect body weight if the extra calories come predominantly from fat rather than carbohydrate. Which multi-step reasoning correctly predicts the relative change in body mass over time?

Which statement correctly describes adipocyte hypertrophy and hyperplasia in fat storage?

Which of the following best summarizes how subcutaneous adipose tissue contributes to thermal regulation?

A clinician evaluates two patients: one with very low body fat and persistent cold intolerance, and another with high visceral adiposity and metabolic syndrome. Which evaluation best captures the contrasting clinical implications?

Which description correctly states roles of phospholipids and cholesterol in cell membranes?

Which pathway or role correctly links cholesterol to other biologically important molecules?

If an adult consumes a very low-fat diet that supplies only 5% of energy as fat, which of the following is the most likely immediate nutritional consequence related to fat-soluble vitamins?

An outpatient consumes 1,800 kcal/day and follows a fat-restricted plan providing 10% of kcal as fat. Calculate the grams of fat per day and discuss whether this amount is likely sufficient to support absorption of fat-soluble vitamins in most adults.

Design a brief dietary modification for someone trying to reduce saturated fat but maintain satiety and fat-soluble vitamin intake at typical energy needs. Which approach best synthesizes these goals?

Which assessment best explains why fats often increase perceived satiety relative to carbohydrate-rich foods?

Using the AMDR ranges, which of the following sets of macronutrient energy distributions is within recommended ranges for carbohydrates, fat, and protein respectively (carb 45–65%, fat 20–35%, protein 10–35%)?

Given that liver glycogen stores are limited (≈100 g) and muscle glycogen varies by muscle mass (≈300–500 g), analyze how a high-calorie diet would differently affect glycogen versus adipose tissue storage over weeks.

A patient is on a strict cholesterol-lowering medication that drastically reduces circulating cholesterol. From a physiological standpoint, which consequence is most plausible if cholesterol becomes too low for prolonged periods?

A vegetarian patient reduces dietary fat to 12% of calories and complains of decreased night vision and easy bruising. Which mechanistic explanation most appropriately links the reduced fat intake to these symptoms?

An individual consumes an extra 300 kcal/day from fat compared to their usual energy needs. Evaluate the approximate monthly weight gain attributable to that surplus, assuming 1 lb body fat ≈ 3500 kcal. Show your reasoning.

Which of the following best analyzes how membrane cholesterol affects membrane fluidity at different temperatures?

A surgeon explains that visceral fat surrounds internal organs and can act as mechanical protection. Which practical implication should be considered when visceral fat is excessive?

A dietitian is asked to create a dinner that maximizes satiety and preserves fat-soluble vitamin absorption while keeping fat at 30% of a 2,200 kcal meal plan. Which synthesis of food choices best meets those goals?

Which analysis best explains why replacing some saturated fats with unsaturated plant oils can improve health while preserving sensory properties of foods?

Given a daily intake of 1,820 kcal composed of 250 g carbohydrate, 70 g protein, and 60 g fat, calculate whether the fat intake meets the AMDR (20–35%). Show calculations.

A patient on a medically supervised very-low-fat diet develops prolonged bleeding after minor surgery and has low serum vitamin K activity. Evaluate the most plausible connection between their diet and the laboratory finding.

A patient on long-term high-dose statin therapy experiences muscle weakness and low sex hormone levels. Which evaluation most accurately links cholesterol suppression to these clinical features?

Propose a single simple swap for someone who wants to maintain satiety and flavor but reduce saturated fat: which is the best option?