Think of your body as a Fortune 500 company. There are layers of management, countless systems that must work together seamlessly, and tons of goals that occasionally conflict.

In other words, it’s complicated. Thankfully, you don’t have to think much about it, because your hormones do all the heavy lifting, from helping you fall asleep at night to deciding whether a particular calorie should be converted into fat or muscle.

The best part: You can learn to control them. And when you do, you’ll look and feel better every day. Read below to find out how your hormones can make you into the man you aspire to be.

Hunger Regulators: Ghrelin and Leptin

These two guys are constantly fighting to tell you how much food you need to eat. Ghrelin, which makes you feel hungry, is secreted by the stomach walls. Leptin, released from fat cells, tells your body that your energy stores are full.

Once in your bloodstream, both hormones flow toward the brain’s hypothalamus, and in healthy guys, whichever one shows up in the greatest numbers wins. But when you stop taking care of yourself, your body becomes resistant to leptin; and ghrelin—the hunger-causing hormone—starts winning the battles.

How to Control Ghrelin and Leptin: Stick To a Bedtime
According to researchers at Penn State, people who sleep fewer than six hours a night see appetite-inducing ghrelin levels surge while leptin declines. And no, sleeping in on the weekends doesn’t compensate for the damage, says Ofer Reizes, Ph.D., of the Cleveland Clinic. If you want a flat belly, you need plenty of shuteye every night.

Metabolism Boosters: Thyroid Hormones

The thyroid, a bat-shaped gland in your neck, churns out the hormones T3 and T4, which travel throughout your body, telling each cell how much energy to produce and expend. That determines your basal metabolic rate—how many calories you burn before factoring in daily activities and exercise, says Steven Lamm, M.D., of NYU’s Tisch Center for Men’s Health.

Even small dips in T3 and T4 can cause your metabolism to stall and the kilograms to pile on. If the dip is sudden, it could be due to a tumor or autoimmune condition, such as Hashimoto’s disease.

How to Control Thyroid Hormones: Dine On Iodine
If your body weight spikes, call your doctor, says Dr. Lamm. A simple blood test can determine whether you have a thyroid disorder.

Otherwise, keep the gland healthy by consuming about 150 micrograms of dietary iodine a day. The mineral is essential for your body’s T3 and T4 production. Saltwater seafood, dairy, and eggs are all good sources.

Muscle Builders: IGF-1 and HGH

Maybe you’ve heard rumors of pro athletes and bodybuilders using illegal injections of human growth hormone (HGH, also called somatotropin). HGH triggers the production of insulin-like growth factor-1 (IGF-1). Together these two hormones break down fat and use the energy to strengthen muscles, ligaments, and tendons, says Jacob Wilson, Ph.D., associate editor of the Journal of Strength and Conditioning Research.

Your body makes HGH naturally, but shortly after you reach the age of 20, your levels begin to drop by 15 percent or so each decade, says Wilson.

How to Control IGF-1 and HGH: Go For the Burn
To naturally spike HGH, work to the point of fatigue, says Wilson. Use the heaviest weights you can manage for 3 or 4 sets of 8 to 12 reps. Between sets, limit your rest to no more than 60 seconds.

“If you feel a burn in your muscles, you’re doing it right,” he says. That means your body chemistry is becoming slightly acidic, which ups HGH production.

Sleep Inducer: Melatonin

Ideally your production of sleep-inducing melatonin would idle during the day and hit its peak between 2 a.m. and 4 a.m., says Men’s Health sleep medicine advisor Christopher Winter, M.D. But that doesn’t always happen.

Your pineal gland cycles melatonin based on your exposure to blue light, the stimulating shortwave beams that are emitted by the sun as well as your smartphone and television. If you spend time in front of a screen after sunset, you throw off your natural sleep cycle, and your 2 a.m. peak could be delayed until it’s time to wake up for work.

How to Control Melatonin: Unplug Early
Starting two hours before bedtime, nix the screens. Even a backlit e-reader can set your sleep cycle back by 1½hours, according to Harvard research.

If your hormones aren’t working for you, they’re working against you.

Libido Lifter: Testosterone

Testosterone channels protein toward your muscle cells, boosts your sex drive, and increases your sperm count. A man’s T levels generally drop with age, but they don’t have to: “Testosterone decline is linked with aging because we tend to become more sedentary, less fit, and more overweight with time,” says Darius Paduch, M.D., Ph.D., a urologist at Weill Cornell Medical College.

In a recent Imperial College London study of nearly 3,200 men over the age of 40, three out of four of those with low testosterone were either overweight or obese.

How to Control Testosterone: Set a Two-Drink Limit
Alcohol can hinder the testosterone-producing chemical reactions that occur in your testicles and liver, says Brian Steixner, M.D., of the Jersey Urology Group.

A blood alcohol concentration of just 0.05—still within the legal driving limit—can cause a 9 percent dip in testosterone in men ages 21 to 25, according to research in the journal Alcoholism.

Fat Burner: Irisin

If you haven’t heard of brown fat, here’s what you need to know: Unlike the white fat that jiggles when you do jumping jacks, the brown stuff is firm and metabolically active.

Fifty grams of brown fat burns about 300 calories a day. And as it turns out, a hormone exists that can turn your white fat brown. It’s called irisin. Its existence in humans was confirmed only last year, says Christiane Wrann, D.V.M., Ph.D., of the Dana- Farber Cancer Institute. If you can get your veins to course with irisin, then you might be able to eliminate that jumping-jack jiggle.

How to Control Irisin: Freeze Your Ass Off
Shivering for 10 to 15 minutes increases your irisin production about as much as an hour of moderate exercise does, according to research from the National Institutes of Health.

If you’re not willing to freeze, then keep your biggest muscles—specifically the ones in your legs—contracting, says Dr. Wrann. Running and cycling do the trick.

Energy Importer: Insulin

Insulin is responsible for moving fat and sugar from your bloodstream to your fat and muscle cells for storage. If your body stops responding to it properly, sugar levels can rise, putting you at risk of type 2 diabetes. So the goal, generally speaking, is to keep your insulin- sugar levels balanced.

But an insulin spike can help you immediately after a tough workout, when the hormone provides a muscle-building window. It delivers more sugars right to your muscles. That’s good: Your body uses this sugar, called glycogen, to keep you energized and fuel your strength.

 How to Control Insulin: Eat Carbs After Your Workout
A University of Oklahoma review found that the ideal postworkout carb intake was about a gram per kg of body mass. For a 90kg guy, that’s 90 grams—or a large potato and a cup of corn.

Throw some protein on that plate too. It will help with muscle protein synthesis, says Javier Gonzalez, Ph.D., of the University of Bath.