In 1977, the low-fat diet was recommended to all Americans. The obesity epidemic started at almost the exact same time. Now, some are shifting nutrition strategy to high-fat eating like the ketogenic diet.
CrossFit Throne gym owner Jon Harwood is a busy guy. He's married, with three kids, and also runs his own business. So, what fuels his lifestyle and training?
"A lot of fat and a lot of meat," Harwood said.
He said eating high fat, low carbohydrate and adequate protein switches the metabolism from burning sugar to burning fat.
It's a variation of the Atkins plan, called a ketogenic diet.
"Instead of storing fat, your body's like 'oh we can just burn this now,'" Harwood said.
Some believe we need a lot of carbohydrates for energy.
"Carbs is a loaded word, right? People think breads, pasta. When I think carbs, I think broccoli, I think asparagus, I think spinach," Harwood said.
Dietitian Allison Childress said she doesn't recommend ketogetnic eating for everyone.
"It's not a wholesome thing. I mean, our body needs grains," Childress said.
She said it may not be the best long-term choice.
"It can disrupt some cardiovascular and brain pathways, but for short term for weight loss, it works," Childress said.
It helped Hardwood lose 55 pounds.
"Probably the best shape of my life," Harwood said.
He said it was no fad diet. He's kept the weight off for ten years and stays energized on a high-fat intake.
Childress agrees that healthy fats can be super-foods.
"Now there's research coming out that some fats can actually reduce your chance of cardiac disease," Childress said.
So, why was low-fat ever recommended?
"Fats were kind of demonized and villainized because that's what the research showed," Childress said.
Now, nutrition science is evolving.
"There's actually going to be no limit whatsoever on the healthy fats, the polyunsaturated and monounsaturated fats," Childress said.
"Avocados, cashews, almonds, almond milk," Harwood listed as some of his favorite healthy fats, well as coconut and olive oil.
"It's a little bit cleaner," Harwood said.
Harwood tells his gym members every metabolism is different. The ideal amount of carbs, fat and protein is going to be different too.
Regardless, good fats are not the enemy.
"Tweak their diet as they need and see what works for them," Harwood said.
All fats aren't created equal. The FDA recently banned industrially produced trans fats. They're found in processed foods like baked goods and frozen foods. A lot of companies have already ditched the stuff, but make sure to read the label whenever you buy anything packaged.