nutrition: lipids and fats

what does high triglycerides mean?

too much fat in your body (blood)

3 fatty acids - triglycerides

• eating an excess amount of food (fats, hfcs), and the body stores it like a box in the liver when there’s too much

  • fatty liver

  • the fat spills into the blood and can cause high blood pressure, weight gain, and diabetes

benefits of lipids

• energy

• energy storage

  • fat tissue

• cell membranes

• raw materials

  • made into hormones, vitamin D, and bile

• vitamin carriers

  • A D E K

• protection and warmth

saturated fats: double bonds?

none

saturated fats: at room temp

usually solid

• straight chains pack tightly

saturated fats: common sources

• butter

• cheese

• fatty meat

• coconut and palm oil

saturated fats: health note

too much raises LDL cholesterol

monounsaturated fats: double bonds?

one

monounsaturated fats: at room temp

usually liquid

monounsaturated fats: common sources

• olive and canola oil

• avocado

• peanuts

• most nuts

monounsaturated fats: health note

helpful when it replaces saturated fat

polyunsaturated fats: double bonds?

two or more

polyunsaturated fats: at room temp

liquid (kinked chains)

polyunsaturated fats: common sources

• fish

• walnuts

• seeds

• soybean

• corn

• sunflower oil

polyunsaturated fats: health note

includes essential omega-3 and omega-6

omega-3

good for heart, brain, and inflammation

• fish oil

• ALA: walnuts, flax, chia, soybean, and canola oil

• EPA and DHA: salmon, sardines, trout, mackerel

aim for about 2 servings of seafood rich in this nutrient a week

omega-6

linoeic acid:

• soybean

• corn and sunflower oil

• nuts

• seeds

most people already get plenty of this nutrient

can convert to other omega

abundant in processed foods - big no

triglycerides: how fat is stored and carried

glycerol + 3 fatty acids

• main form of fat in food in the body

• energy-dense storage in fat cells (adipose tissue)

• carried in blood by lipoproteins

• extra calories from ANY source can be stored as this

phospholipids

2 fatty acids + a phosphate “head”

• mix with water and fat: they build every cell membrane

• lecithin: (egg yolk, soybeans) is a good food emulsifier

• hydrophilic

sterols

• cholesterol: made by your liver, found only in animal foods

• needed for hormones, vitamin D, and bile

• for most people, saturated fat raises LDL more than food cholesterol does

• our body can produce too much cholesterol = high cholesterol, which can raise LDL cholesterol

trans fat

• forms when hydrogen is added to liquid oil to make it solid and shelf-stable

• industrial trans-fat raises LDL, lowers HDL, and raises heart disease risk

• “0g” = <0.5g

• hydrogenated oils could cause cancer

fat digestion and absorption

1. mouth, stomach

2. small intestine

3. digestion

4. absorption

fat digestion and absorption: mouth, stomach

• little fat digestion

• fat flats and slows stomach emptying so you feel full

fat digestion and absorption: small intestine

bile breaks fat into tiny droplets (emulsification)

• breaks it down into fatty acids and monoglycerides

fat digestion and absorption: digestion

pancreatic lipase splits triglycerides into fatty acids and monoglycerides

• gets over into intestinal walls

fat digestion and absorption: absorption

fat enters intestinal cells and is repackaged to travel through the body

• goes into the liver and then is packaged and then goes into bloodstream

short and medium chain fatty acids

absorbed into blood → liver first

• liver → blood

long chain fatty acids

rebuild into triglycerides → chylomicrons → lymph → blood (bypass the liver at first)

• liver → blood

lipoproteins

• chylomicron

• VDLD

• LDL

• HDL

chylomicron: made in?

intestine

chylomicron: main cargo

dietary triglycerides

chylomicron: remember

like a delivery truck after a meal; least dense

VLDL: made in?

liver

VLDL: main cargo

triglycerides made by the liver

VLDL: remember

shrinks into LDL as cells take up fat

LDL: made in?

blood (from VLDL)

LDL: main cargo

cholesterol to cells

LDL: remember

“bad” when high: can build up in artery walls

HDL: made in?

liver and intestine

HDL: main cargo

collects extra cholesterol

HDL: remember

“good”: returns cholesterol to the liver

high triglycerides on a lab report:

= lots of triglyceride rich particles (chylomicrons and VLDL) in the blood

total cholesterol: what it measures

all lipoprotein cholesterol combined

total cholesterol: typical adult target (mg/dL)

under 200

LDL (“bad”): what it measures

cholesterol carried to cells

LDL (“bad”): typical adult target (mg/dL)

under 100 is optimal (goal depends on risk)

HDL (“good”): what it measures

cholesterol returning to liver

HDL (“good”): typical adult target (mg/dL)

60 or higher: under 40 (for men) or 50 (for women) is low

triglycerides: what it measures

fat carried in blood, mostly VLDL

triglycerides: typical adult target (mg/dL)

under 150 is normal: 150-199 borderline; 200+ high

what pushes triglycerides up?

• extra calories overall

  • any source can be stored as fat

• added sugars and sugary drinks

  • liver turns extra sugar into fat

• refined carbohydrates

  • white rice, white bread, chips, pastries

• alcohol

• inactivity and extra weight

other contributors to high triglyceride

• type 2 diabetes, insulin resistance

• low thyroid, kidney disease

• some medicines: genetic

2025-2030 dietary guidelines

• eat real food

  • whole, nutrient dense foods

• healthy fat sources

• cooking and added fats

  • oils with essential fatty acids

• saturated fat limit

  • no more than 10% of daily calories

• limit highly processed foods

same dietary guidelines

• saturated fats under 10% of daily calories

• fat is essential

• olive oil and other unsaturated fats are encouraged

• added sugars and sodium stay limited

new/different guidelines

• dairy: full-fat dairy with no added sugars

• butter and beef tallow are good options for cooking

• “highly processed foods” is a headline category: chips, cookies, candy

• added sugars: no amount recommended; no more than 10g in one meal

choose more often:

• olive oil (1 tbsp)

• sunflower seeds (2 tbsp)

• mixed nuts (2 tbsp)

• avocado (6 slices)

• salmon (2oz)

choose less often:

• butter (1 tbsp)

• bacon (2 slices)

• potato chips (10 chips)

• cheese (1 slice)

• steak (1 ½ oz)

mediterranean-style eating

• olive oil

• nuts, seeds, legumes

• whole grains

• fish and seafood

  • 2x a week

• vegetables and fruit

• less red and processed meat

what should patients hear?

1. fat is essential. do not cut it all out

2. different fats have different effects

3. choose unsaturated fats more often: olive oil, nuts, seeds, avocado, fish

4. keep saturated fat under 10% of calories and avoid industrial trans fat

5. low-fat does not mean healthy. look at whole food and overall pattern

“low fat” does not autmatically mean healthy

• less fat in the product

• flavor replaced with sugar, starch, or salt

• calories often about the same

• still a highly processed snack