My husband is 45 yrs sometimes he goes to the gym and he eats good but for somw reason he doesn loose weight?

Food combinations is: important as what foods he eats, or doesn't eat. He needs to be off all processed foods, nonorganic, fried, GMO foods including soy, corn, potato, wheat and reduce starches to tiny portions, and no alcohol, drink lots of purified spring water. If he has a good appetite, and eat a lot, it will be harder to lose weight. But, if he modifies his diet, he will have better luck, and continue exercising.